AMERICAN SCIENCE SERIES 



BOTANY 



HIGH SCHOOLS AND COLLEGES 



BY 

CHARLES E. BESSEY, Ph.D., 

PROFESSOR OP BOTANY IN THE UNIVERSITY OF NEBRASKA 



SEVENTR EDITION, REVISED 




NEW YORK 
HENRY HOLT AND COMPANY 

1905 



LIBRARY of CONGRESS 
Two Copies KewiviKi 

MAR 25 1:^08 

Uopyri^iK tMir.v ^ 



Uo f/^'b 






I "i^ 



Copyright, 1880, 

BY 

HENRY HOLT & CO. 



Copyright, 1908, 

BY 

HENRY HOLT AND COMPANY 



PREFACE. 



This book is designed to serve as an Introduction 
to the Study of Plants. It does not profess to give a 
complete account of the Vegetable Kingdom, but 
only such an outline as will best subserve the pur- 
poses of the work. 

In its preparation there have been kept in view 
the wants of the large number, in the schools and 
out, who wish to obtain, as a branch of a liberal cul- 
ture, a general knowledge of the structure of plants, 
with some idea as to their classification into the 
larger divisions and subdivisions of the Vegetable 
Kingdom. For this class of students and general 
readers, what is here given will in most cases be 
amply sufficient to enable any one to understand the 
greater part of the current biological literature, in so 
far as it relates to vegetable organisms. For the 
student who desires to pursue the subject further, 
or who intends to make botany a special study, this 
book aims to lead him to become himself an observer 
and investigator, and thus to obtain at first hand his 
knowledge of the anatomy and physiology of plants : 
accordingly the presentation of the matter has been 
made such as to tit the book for constant use in the 
Laboratory, the text supplying the outline sketch, 
which may be filled up by each student, with the aid 
of the scalpel and compound microscope. 

This book is an expansion and considerable modi- 
fication of the material of several courses of lectures 



IV r HE FACE. 

annually delivered to college students. In general 
plan 7 Part I. follows pretty nearly that of Sachs' ad- 
mirable ''Lelirbuch," and in many instances it has 
seemed to me that I could not do better than to 
adopt the particular treatment which a subject has 
received at the hands of the distinguished German 
botanist. This has been rendered possible through 
the liberality of my publishers, and the courtesy of 
Engelmann of Leipzig, the publisher of many of 
Sachs' workSj by which many of the cuts of the 
" Lehrbuch" are here reproduced. This book will 
thus, to a considerable extent, serve as an introduc- 
tion to that work. Free use has also been made of 
the recent works of De Bary, Hofmeister, Strasbur- 
ger, Nageli, Schwendener, and others, to whose writ- 
ings numerous references are made. 

In Part II. the general disposition of the lower 
plants is a considerable modification of that proposed 
by Sachs ; that of the higher plants is made to con- 
form to the system of classification in vogue in this 
country and in England, as outlined in Dr. J. D. 
Hooker's "Synopsis of the Classes, Sub-classes, Co- 
horts and Orders," in the English edition of 
Le Maout and Decaisne's "Traite Generale de Botan- 
ique," and as given much more fully in Bentham and 
Hooker's still unfinished "Genera Plantarum." The 
notes upon the economic values of the more impor- 
tant plants of each order are based upon my own lec- 
tures upon Economic Botany. I have also fi-eely 
used the similar notes in Le Maout and Decaisne's 
work, cited above ; Balfour's " Class-Book of Bot- 
any," Archer's "Economic Botany," Smith's "Do- 
mestic Botany," Laslett's "Timber and Timber 
Trees," etc., etc. 

Necessarily, there is but little that is really new in a 
ca^eatise like this. Aside from a more or less important 
and original arrangement of the matter, so as to 



TBEFACE. V 

^secure a more logical presentation of tlie subject, 
there are but two considerable innovations, consist- 
ing (I.) in the recognition (in Chapter YI.) of seven 
quite well marked kinds of tissue. In this, however, 
while not adopting De Barj's classification, I have 
followed his method of treating the subject, as given 
in his recent work on the comparative anatomy of 
plants (" Vergleichende Anatomie der Vegetations- 
organe der Phanerogamen und Fame/') (II.) The 
second considerable innovation occurs in Part II. ; it 
consists in raising the Protophyta, Zygosporese, Oos- 
pores and Carposporese to the dignity of Primary 
Divisions of the vegetable kingdom, co-ordinate with 
the Bryophyta, Pteridophyta and Phanerogamia. 
The usefulness of both of these departures from the 
common practice has been subjected to the test of 
the laboratory, and the lecture and class-room, with 
the most satisfactory results ; and I am led to hope 
that in the hands of others they may also serve to 
give a clearer and more accurate notion of the struc- 
ture of plants. Should they do this they will need no 
further apology or defense. 

Of the illustrations, many are entirely new ; many 
others have been re-drawn, from various sources, 
with slight modifications, expressly for this work, 
and all from other sources are specially acknowl- 
edged in their places. 

I desire here to acknowledge my indebtedness to 
Dr. Asa Gray, whom it is an honor to own as my 
sometime teacher, for kindly aid and counsel in the 
preparation of the lectures upon which this work is 
based ; and in the same way I am indebted to Dr. 
Gr. L. Goodale, Dr. W. G. Farlow and Professor A. 
N. Prentiss. For aid in the immediate preparation 
of the material for the press, acknowledgment is due 
many of my personal friends : Mr. J. C. Arthur fur- 
nished the original drawings of the water-pores of 



VI PREFACE. 

Fuchsia, and of various tissues of Ecldnocystis; 
Professor H. L. Smitli, of Hobart College, New 
York, contributed the sketcli of the classihcation of 
the Diatomaceae ; Dr. T. F. Allen furnished a synop- 
sis of the classification of the Characese ; Dr. B. D. 
Halsted also furnished material and notes uj^on our 
native species of Characese ; my colleague, Professor 
W. H. Wynn, kindly determined some of the more 
difficult etymologies ; to my wife I am deeply in- 
debted for efficient aid in the laborious tasks of 
proof-reading and indexing. 

Should this book serve to interest the student in 
the study of plants as living things, should it succeed 
in directing him rather to the plants themselves than 
to the books which have been written about them, 
should it contribute somewhat to the general read- 
er' s knowledge of the structure and relationship of 
the plants around him, the objects kept in view in its 
preparation will have been attained. 

C. E. B. 

April 12, 1880. 



PEEFACE TO THE SEVENTH EDITION. 

In the second, third, and fourth editions which appeared, 
respectively, in 1881, 1883, and 1885, a considerable num- 
ber of corrections and minor additions were made. In the 
fifth edition (1888) the terms Zygophyta, Oophyta, and 
Carpophyta, previously used in " The Essentials of Botany,^^ 
were adopted. The sixth edition (1889) included many 
minor additions and foot-notes. The present edition con- 
tains new matter upon the nucleus, cell-division, Entomoph- 
thoracese, Ustilaginese, Degraded Ascomyc^tes, and Imperfect 
Fungi, On pp. 339-340 a more natural arrangement of the 

Thallophytes is proposed. n t^ -n 

L. Hi. J3. 

University of Nebraska, 
Lincoln, January 29, 1893. 



CONTENTS. 



PART I. GENERAL ANATOMY AND PHYSIOLOGY. 



CHAPTER I. 
Protoplasm. 

PAOB 

General Characters — Chemical Composition — Consistence — Power 
of Imbibing Water — Vacuoles — Physical Activity — Naked 
Protoplasm — Protoplasm Enclosed in Cell Walls 1 

CHAPTER II. 
The Plant-Cell. 

General Statement — Ectoplasm and Endoplasm — Bands and Strings 
of Protoplasm — Nucleus — Size of Cells — Forms of Cells — The 
Cell the Unit in Plants 15 

CHAPTER III. 

The Cell- Wall. 

Composition — Growth in Surface — Growth in Thickness — The 
Markings on Cell Walls — Theories as to the Mode of Thick- 
ening — Stratification of the Cell Wall — Formation of Chem- 
ically Different Layers — The Formation of Mucilage — Incom- 
bustible Substances in the Wall 21 

CHAPTER IV. 
The Formation op New Cells. 

Cell-Formation by Division : (a) Fission ; (&) Internal Cell-Forma- 
tion — Cell-Formation by Union — Examples 36 



Vlil CONTENTS. 

CHAPTER V. 
The Pkoddcts op the Cell. 

PAGB 

§ 1. Chlorophyll — § 2. Starch, Composition, Form, Molecular 
Structure — Granulose and Starch-Cellulose — Formation of 
Starch Granules in the Chlorophyll-Bodies — Formation of 
Ordinary Starch Granules — § 3. Aleurone and Crystalloids — 
§ 4. Crystals in Cells— § 5. The Cell Sap- § 6. Oils, Resins, 
Gums, Acids and Alkaloids 50 

CHAPTER VI. 
Tissues. 

^ 1. The Various Agoregations of Cells : {a) Single Cells ; {h) Fam- 
ilies ; (c) Fusions ; {d) Tissues ; The Cell- Wall in Tissues — 
§ 2. The Principal Tissues — Parenchyma — Collenchyma — 
Sclerenchyma — Fibrous Tissue — Laticiferous Tissue — Sieve 
Tissue — Tracheary Tissue — §3. The Primary Meristem 65 

CHAPTER VII. 

The Tissue Systems. 

§ 1. The Differentiation of Tissues into Systems — § 2. The Epi- 
dermal System of Tissues — Epidermis — Trichomes — Stomata 
— § 3. The Fibro- Vascular System of Tissues — General 
Structure — The Fibro- Vascular Bundles of Pteris, Polypodium, 
Adiantum, Equisetum, Selaginella, Lycopodium, Zea, Acorus, 
Ricinus and Ranunculus — Of Xylem and Phloem — Collateral, 
Concentric, and Radial Bundles — Development of Fibro- 
Vascular Bundles — ^ 4. The Fundamental System — The Tis- 
sues it Contains — Cork — Lenticels 89 

CHAPTER VIII. 
Intercellular Spaces, and Secretion Reservoirs 128 

CHAPTER IX. 
The Plant-Body. 

§ 1. Generalized Forms— Thallome—Caulome—Trichome—Root,^ 
Particular Relations of Phyllome to Caulome — General Modes 
of Branching of Members— § 2. Stems— The Punctum Vegeta- 
tionis— Buds— Adventitious Stems— § 3. Of Leaves in General 
— § 4. The Arrangement of Leaves— § 5. The Internal Struc- 
ture of Leaves— § 6. The Roots of Plants, Structure, Root-Cap, 
Growth — Formation of New Roots — Arrangement of Roots. . . 133 



CONTENTS. IX 

CHAPTER X. 
The Chemical Constituents of Plants. 

PAGE 

§ 1. The Water in the Plant— Amount of Water in Plants— Water 
in the Protoplasm — Water in the Cell Walls — Water in the 
Intercellular Spaces — Equilibrium of the Water in the Plant — 
Disturbance of Equilibrium — Evaporation of Water — Amount 
of Evaporation — The Movement of the Water in the Plant 
— § 2. As to Solutions — § 3. Plant Food — The Most Important 
Elements — The Compounds Used — How the Food is Obtained 
—How Transported in the Plant 166 

CHAPTER XI. 
The Chemical Processes in the Plant. 

§ 1. Assimilation — § 2. Metastasis — Its General Nature — Trans- 
formation of Starch — Nutrition of Protoplasm — The Storing of 
Reserve Material — The Use of Reserve Material — The Nutri- 
tion of Parasites and Saprophytes — The Formation of Alkaloids 
—Results of Metastasis 178 

CHAPTER XII. 
The Relations op Plants to External Agents. 

§ 1. Temperature — General Relations — Absorption of Water as Af- 
fected by Temperature — Evaporation — Assimilation — Metasta- 
sis — Death from too High a Temperature — Death from too 
Low a Temperature — %2. Light: General Relations of Light 
to Assimilation, Light, and Metastasis — § 3. Heliotropism — 
§ 4. Geotropism — § 5. Certain Movements of Plants : General * 
Statement, Spontaneous Movements, Movements Dependent 
upon External Stimuli, Movements of Nutation, Movements 
of Torsion , 184 



PART II. SPECIAL ANATOMY AlfD PHYSIOLOGY, 



CHAPTER XIII. 
Classification^ 

Principles of a Natural Classification — Critical — A Comparison of 
several Systems f>03 



X CONTENTS. 

CHAPTER XIV. 
The Protopityta. 

PAGE 

§ 1. Myxomycetes — § 3. Schizomycetes — § 3. CyanopliyceaB 206 

CHAPTER XV. 

The Zygophyta. 

§ 1. Zoosporeae — § 3. Conjugatae 320 

CHAPTER XVI. 

The Oophyta. 

§ 1. Vol vox and its Allies — § 2. (Edogoniese — § 3. Coeloblastese — 

§ 4. Fucacese .". 243 

CHAPTER XVII. 

The Carpophyta. 

§ 1. Coleochsete — § 2. Floridese — § 3. Ascomycetes — § 4. Basidio- 
mycetes — § 5. Characeae — § 6. The Classification of Tballo- 
pliytes 270 

CHAPTER XVIII. 

The Bryophyta. 
§1. Hepaticse— § 3. Musci „ 341 

CHAPTER XIX. 

The Pteridophyta. 

§ 1. Equisetinae— § 2. Filicinae— § 3. Lycopodinae 361 

CHAPTER XX. 

The Phanerogamia. 

§ 1. General Characters — § 2. Gymnospermae — § 3. Angiospermae 
— Glossology of Angiosperms — The Tissues of Angiosperms — 
Classification and Economic Botany of Monocotyledons — Class- 
ification and Economic Botany of Dicotyledons 389 

CHAPTER XXI. 

Concluding Observations. 

The Number of Species of Plants — The Affinities of the Groups of 

Plants— The Distribution of Plants in Time 566 



BOTANY. 



PART I. 
GENERAL ANATOMY AND PHYSIOLOGY. 



CHAPTER I. 

PROTOPLASM. 

1, — If we examine a thin slice of any growing part of a 
plant (Fig. 1) nnder a microscope of a moderately high 
power (400 to 500 diameters), there may be seen large num- 
bers of cavities which are more or less filled with an almost 
transparent semi-fluid substance. In very young parts, as 
in buds and the tips of roots, this substance entirely fills the 
cavities, and makes up almost the whole mass, while in older 
parts it occurs in less quantity, and usually disappears in 
quite old tissues. This substance is the living portion of 
the plant, the active, vital thing which gives to it its sensi- 
bility to heat, cold, and other agents, and the power of mov- 
ing, of appropriating food, and of increasing its size ; it is, in 
fact, that which is sensitive, which moves, appropriates food, 
and increases in size. This sensitive, moving, assimilating, 
and growing substance is named Protoplasm.* 

It is a fact of great biological interest that in animals the essential 
constituent of all living parts is a substance similar to the protoplasm 
of plants. We cannot distinguish the two by any chemical or physical 
tests, and can only say that, taken as a whole, the protoplasm of plants 

* So named by its discoverer, Dr. Hugo Von Mohl, in 1846. It is the 
Bioplasm of Dr. Lionel Beale and his followers. 



BOl'ANY. 



differs from that of animals in its secretions. And yet these secre. 
tions are not strictly confined to plants ; cellulose, starch, chlorophyll, 
and other products of vegetable protoplasm formerly regarded as pe- 
culiar to plants are now known to occur in undoubted animals. Botanists 
and zoologists have labored long in vain to discover absolute differences 
between the animal and the vegetable kingdoms, between the higher 
plants and the higher animals there are great and constant differences • 

in none of the higher animals, for ex- 
ample, is chlorophyll produced ; but 
in the lower orders of both kingdoms 
not one of the differences observed to 
hold between the higher plants and 
animals exists. 

2. — The exact chemical compo- 
sition of jDrotoplasm has not hith- 
erto been made out, but it is 
known to be an albuminous, 
watery substance, combined with 
a small quantity of ash. It is 
probably a complex mixture of 
chemical compounds, and not a 
single compound. It contains at 
some time or another all the chem- 
ical constituents of plants. Oil, 
granules of starch, and other or- 
ganic substances are frequently 
present in it, but they are to be re- 
garded as products rather than 
proper constituents of protoj^lasm. 




Fig. 1.— A little more than half of 
a longitudinal section of the apex of 
a young root of the Indian corn. 
The part above s is the body of the 
root, that below it is the root-cap ; 
V, thick outer wall of the epidermis; 
m young pith-cells ; /, young wood- 
cells ; g, a young vessel ; «, i, inner 
younger part of root-cap ; a, a, out- 
er older part of root-cap.— After 
Sachs. 



{a) Water makes up a considerable 
part of the bulk of ordinary protoplasm, 
and is much more abundant in its 
active than in its dormant conditions. 
In the protoplasm of Fuligo 'carians 
(one of the Slime Moulds) just before 
the formation of its spores there is 70 
per cent of water ; in dry seeds, on the other hand, the amount is not 
more than about 8 to 10 per cent. 

(&) As to its molecular constitution, Strasburger holds* that proto- 
plasm is composed of minute solid particles (not, however, of a crystal- 
line form), separated from each other by layers of water (see Cell-wall 

* " Studien iiber Protoplasma," 1876. 



FBOTOPLASM. 3 

paragrapli 87, and Starch, paragraph 69). The thicker the layers of 
water are, the more watery is the protoplasm, and mce versa. 

{c) Tests. 1. If a protoplasmic mass is moistened with a solution of 
iodine, it at once assumes a deep yellow or brown color. 

2. If treated with a solution of copper sulphate and afterwards with 
potash, it assumes a dark violet color. 




Pig. 2.— Parenchyma cells from the central cortical layer of the root of Fritillaria 
im2)erialis, longitudinal sections. A, very young cells lying closi^ above the apex ol 
the root, still without cell sap or vacuoles. B, cells of the same description about 
two millimetres above the apex of ttie root ; by the entrance of cull sap the vacuoles 
s, s, s have been formed. C, cells of the same description about seven to eight mil- 
limetres above the apex of the root. In all the figures, h, cell-wall ; p, protoplasm ; 
k, nucleus ; /fc A:, nucleoli ; s, vacuoles ; xy, swelling of the nucleus under the infla- 
ence of the water in preparing the specimen. X 500.— After Sachs. 



3, Treated with a solution of sugar, and afterwards with sulphuric 
acid, it becomes rose-red. 

4. The presence of protoplasm may be demonstrated in a tissue by 
the application of various staining fluids, as magenta, carmine, etc. 



BOTANY. 



5. In a dilute solution of potasli protoplasm is dissolved ; if, how- 
ever, the solution is concentrated, the form of the protoplasm remains 
unaltered for weeks, but upon the addition of water it at once dissolves. 

6. Protoplasm coagulates upon the application of heat (50 degrees 
Centigrade), or when immersed in alcohol or dilute mineral acids. 

3. — In consistence protoplasm is a soft-solid substance, 
varying from an almost perfect fluidity on the one hand to 
a considerable degree of hardness and even brittleness on 

the other. This difference in con- 
sistence is mainly due to the vary- 
ing amounts of water imbibed by 
it, hence the same mass may at 
different times vary greatly in this 
regard. Generally there may be 
seen in 23rotoplasm a large number 
of minute granules enclosed in a 
transparent medium (Fig. 2, A) ; 
in some instances, however, the 
granules are entirely wanting, or 
nearly so. By the withdrawal of 
these granules for a little distance 
from the surface toward the cen- 
tre, a mass of granular protojjlasm. 
^. ^ _ ,. , ,. ^ (the endoplasm) may appear to be 

Fig. 3.— Optical section of a re- ^ ^ i t 

tracting branch of a large piasmo- surroundcd bv a livalme envelope, 

dium of Fuligo imriam (^Mlialium . , , i • i • 

septicum of authors) ; the narrow the protoplasmiC SKIU, Or ecto- 

inner granular mass of protoplasm ^ ..n tt x i • i j. £ -n • 

is seen to be surrounded by a broad plasm (the Hautscflicllt 01 FriUgS- 

hyaline portion, the ectoplasm, i • j rr ± i .c oj. 

which in this case Is radiaiiystreakl heim, and Hauptplasma of btras- 
tte b?d7of"me^piasmcSfumf i?s burger) (Fig. 3). It is almost al- 

S!SlZZn.&TytXf^Tet ^^^^ ^^^^^^ ^^^^U protopksm is 

veiope. X 200.-After Hofmeister. exposed in Water or air ; but it, or 
something very much like it, appears to be generally 
present, even in closed cells. 

(a) The fine granules are probably not proper constituents of proto- 
plasm, but finely divided assimilated food-materials immersed in the 
proper protoplasm, which is itself colorless and transparent. Proto- 
plasm destitute of granules may be found in the cotyledons of the 
bean (Phaseolus), In other cases, e.g., in the zygospores of Spirogyra, 
the granular and coloring matters are so abundant that the hyaline 
basis can no longer be distinguished. 




' PR0T0PLA8M. 5 

\b) Strasburger* maintains that tlie hyaline envelope is not simply a 
portion of the basis or ground substance of the protoplasm deprived 
of its granules, but that it is a definite modification of it, and endowed 
with various properties auite distinct from those of the ground sub- 
stance. 

4. — Active protoplasm possesses the power of imbibing 
water into its substance, and as a consequence, of increasing 
its mass. This power varies with the changes in external, 
and also in internal conditions ; many seeds, for example, 
which do not swell np (through absorbing water) in cold 
water, will do so when placed in that of a higher tempera- 
ture ; but in some seeds it appears that imbibition of water 
will not take place until after a period of rest. 

5. — When the amount of water imbibed is so great that 
the protoplasm may be said to be more than saturated with 
it, the excess is separated within the protoplasmic mass in 
the form of rounded drops, termed Vacuoles (Fig. 2). In 
closed cells these may become so large and abundant as to 
be separated only by thin plates of the protoplasm (Fig. 2,, 
B). As such vacuoles become still larger, the plates are 
broken through, and eventually, we may have but one large 
vacuole surrounded by a thin layer of protoplasm, which 
lines the interior of the cell wall (Fig 2, 0). In this way^ 
some masses of protoplasm assume a bladder-like or vesicular 
form, so unlike their original form that until -very recently 
their real nature has not been understood, f Frequently 
when the plates which separate vacuoles break down, instead 
of breaking entirely away they become pierced with several 
large openings, leaving strings or bands of protoplasm which 
extend across the cavity. 

Occasionally, when vacuoles unite, small masses of the protoplasm 
which previously separated them become detached as free rounded 

* ** Studien liber Protoplasma," 1876. See also Qr. Jour. Mic. Sciencet 
1877, p. 124 et seq. 

f Von Mohl gave to this layer the name Primordial Utricle, and it is 
still frequently used, but the term is objectionable, and Sachs' name of 
Protoplasmic Sac is to be preferred. Treatment with glycerine, strong 
alcohol, or any other substance which removes the water, will cause 
the protoplasmic sac to contract and become visible. 



6 



BOTANY. 



masses in tlie large vacuole ; tliese again may produce vacuoles witliin 
tliemselves, and thus give rise to a peculiar and at first sight perplex- 
ing structure (Fig. 4). 

6.— Tlie most remarkable peculiarity of living protoplasm is 
its physical activity. When the proper conditions are ]3res- 
ent, a living mass of protoplasm is apparently never at rest, 

but, on the contrary, 




continually altering its 
shape and changing the 
position of its constit- 
uent parts. The move- 
ments are all of the 
same general nature : 
each one maybe regard- 
ed as the aggregate re- 
sult of the chemical and 
physical changes taking 
jolace in the substance 
of the protoplasm. 

We may study the ac- 
tivity of protoplasm 
under two conditions, 
which will give us the 
two cases. (1.) The 
Activity of Naked Pro- 
Fig. 4.— Forms of the protoplasm contained in toplasm, and (2.) The 
■cells. A and B, of Indian Corn {Zea mais) ; A, 
cells from the first leal-sheath of a germinating 
plant, showing the frothy condition of the proto- 
plasm, the many vacuoles separated by thin 
plates. B, cells from the first internode of the 
germinating phmt; the protoplasm is broken np 
into many rounded masses, in each of which there !N" ak G d. 
is a vacuole, b ; these are the so-called " sa'p-vesi- 
cles." C, a cell from the tuber of the Jerusalem ilie lOW OrgaUlSmS 
Artichoke {Reliant/ius tuberosus)Sii'tev the aciionof , ,i nr 

iodine and dilute sulphuric acid ; h, cell-wall ; k, KUOWU aS tllC MyXOmy- 
nucleus;^, contracted protoplasm.-After Sachs. ^^^^^^ ^^, gj-^^^ Moulds, 

present the best examples of the activity of naked vegetable 
protoplasm. In their plasmodia (as the masses of naked proto- 
plasm are called), many kinds of movements may be observed, 
the commonest of which is streaming. In plasmodia com- 
posed of thin {i.e., watery) protoplasm, streams or currents 
of the latter may be seen running in various directions 



Activity of Protoplasm 

enclosed in a Cell-wall. 

7.— The Activity of 

Protoplasm. 



PROTOPLASM MOVEMENTS. 



(Fig. 5). The streams are made clearly visible by the motion 
of the granules which are carried along by the moving hya- 
line portion of the protoplasm. After running in one 









^7^^' \^^ ^°^^^^ ?^^^ ?^ ^^^ naked protoplasm {Plasmodium) of Bidvmivm ser 
oula / the arrows show the direction of the currents, x 30.— After Hofmeister. 

iirection for some minutes (about five) the current stops, 
'nd then it usually sets in an exactly opposite direction foi 
ibout the same length of time, and carries back the previ- 
)usly moved protoplasm. 



8 



BOTANY. 



The formation of the new current may be explained as follows : 

Let A J5 be a stream in which the movement is from A 

to B ; clearly there will be an aggregation of protoplasm about B. 
When the current in the direction A B stops, the new one, in the 
reverse direction, B A, begins at ^, by the movement toward it of the 
particles nearest to it ; next the particles further off move toward A ; 
after this, those still further off, and so on. The current extends 'back- 
ward. So, too, when a stream begins de novOy it is propagated back- 
ward from the point of beginning. 

8.— Mass-Movement (Amc3eba-Movement). In the flowing 

back and forth in the 
streams the movement 
may be greater in one 
direction than in the 
other ; this causes a 
slow motion of the 
whole Plasmodium in 
the direction of 
the greatest movementc 
When this takes place 
in the case of streams 
which begin in the mar- 
gin of the Plasmodium, 
protuberances of yari- 
ous shapes arise ; these 
may be extended into 
branches (pseudopo- 
did), which may again 
be branched one or 

Outline of a Plasmodium of Didymium ^lOrC times. By the 

'pula forming pseudopodia. The heavy black; nnaofomoc^iTia nf +hp«A 

line indicates the outline at the beginning of the ^ii^'fei'^iii^feiiito ^-L LUese 

observation ; the pseudopodium a-b formed in 8 brauchcs a COmpleX 

seconds, c~d in 30, and c-e m 55 seconds. X 10. . ^. 

—After Hofmeister. moviiig and changing 

network is formed. (See Fig. 140, page 208) There is pos- 
sibly to be separated from the above-described mass-move- 
ment that more or less rapid change of external contour 
which has, from its resemblance to the motions of the 
Amoeba, been denominated the Amoeba-movement (Fig. 6). 
It is best observed in the so-called ^^Amoeba-form " stage ol 
the swarm-spoi ^s of the MYxomycetes. 




PROTOPLASM MOVEMENTS. 9 

While in thinner protoplasm the streaming and mass- 
movements are always horizontal, or, at least, parallel with 
the surface upon which the plasmodium rests, in the case of 
tougher protoplasm they may give rise to branches which 
have an upward direction, as in the formation of sporangia. 

9.— Effect of External Influences. The movements of 
the protoplasm of the Myxomycetes, and probably to a 
greater or less extent of all plants, are suspended by certain 
external influences. Violent jarring, pressure, a thrust as 
with the point of a pin or pencil, electrical discharges, 
sudden changes of the temperature, and sudden changes in 
the concentration of the surrounding fluid, stop the move- 
ments, and cause the plasmodium to contract into one or 
more spheroidal masses. When these influences cease, if 
they have not been so violent as to destroy the organization 
of the protoplasm, it returns after a greater or less length 
of time to its original form, and the movements are resumed. 

{a) The effect of meclianical disturbances (jarring, pressure, and 
thrust) may be best studied in the tougher or least fluid plasniodia 
{e.g., of Stemonitis fusca). 

(b) The effect of electrical discharges may be studied by placing a 
small Plasmodium {e.g., Didymium serpula) upon a glass plate provided 
with platinum points which are in connection with the poles of an 
induction apparatus. When a discharge takes place through a narrow 
branch (pseudopodium) it contracts so violently as to be broken up into 
a row of little spheres ; if it takes place through the mass of the plas- 
modium it becomes more or less spherical by its contraction. In any 
case, if the shock has not been too severe, the protoplasm after a while 
returns to its normal shape again.* 

(c) The Plasmodium of Didymium serpula, when removed from a tem- 

* Kuhne performed the following curious experiment. Taking a 
portion of the plasmodium of Didymium serpula, in its resting state, 
he mixed it with water so as to make a pulpy or pasty mass. With 
this he filled a piece of the intestine of a water-beetle, and tying the 
ends, laid it across the electrodes of an induction apparatus. The pre- 
paration was kept in a film of water in a dan;p chamber for twenty-four 
hours, at the end of which time it was considerably distended. He now 
allowed the electrical curr(-iit to pass through it, when it contracted 
itself "like a colossal muscle-fibre." Upon extending it by pulling at 
the ends, and then sending through it a stronger electrical current, it 
contracted itself one third of its length. 



10 BOTANY. 

perature of 20° C. to one of 30° C. (08" to 86' FaUr.X. withdraws its paeud- 
opodia and ceases its activity in the space of five minutes. In an hour 
after the restoration of tlie normal temperature (20" C.) the movements 
begin again. If the temperature is raised to BS"" C. (95° Fahr.) the 
organization of tlie plastnodium is destroyed. 

The Plasmodium of Faligo variaus, Sommf. {^thalium septicum, 
Fr.), when placed in a chamber surrounded by ice, contracts into a 
rounded form and ceases all motion ; iipon gradually raising the tem- 
perature again the normal state is resumed. 

{d) In glycerine, a concentrated solution of sugar, a five percent solu- 
tion of potassium nitrate, or a five per cent solution of sodium chloride, a 
Plasmodium contracts, and becomes rounded and motionless. A sudden 
decrease in the concentration of the solution by which a plasmodium 
is surrounded also results in a stoppage of its movements. A plasmo- 
dium of Bidymium serxfula, when placed in a one per cent solution 
of potassium nitrate, and allowed time to regain its activity, suddenly 
rounds itself up and stops its movements when the preparation is 
washed out with distilled water ; after the lapse of a few minutes (ten 
to twelve) the activity begins to show itself again, and in half an hour 
the normal state is restored. 

10.— Ciliary Movement. The swimming of swarm-spores, 
spermatozoids, and many other naked protoplasmic bodies, is 
due to the rapid vibratory motion of extremely small whip- 
like extensions of the hyaline portion of the protoplasm. 

Examples of ciliary movement are very common. In some swarm- 
spores, as in those of Vaucheria, the whole surface is covered with short 
cilia ; in others, as in (Edogonium, the cilia form a crown about the hya- 
line anterior extremity ; those of Pandorina and Cladophora, and the 
spermatozoids of Bryophytes and Pteridophytes, have two or more cilia ; 
while the swarm-spores of Myxomycetes have but one. 

The rapidity of the swimming motion produced by cilia is consider- 
able, as shown by measurements made by Holmeister* in the case of 
swarm-spores, viz. : 

FiiUgo variaiis {^thalium septicum). .. .7 to .9 mm. per second. 

Lycogola epidendrum -33 mm. 

CEdogonium vesicatum 15 to .20 mm. 

Vaucheria sp 10 to .14 mm. " 

1 1 .—The Activity of Protoplasm Enclosed in a Cell-walL 
The movements of protoplasm in closed cells differ but 
little from those in naked ones ; the differences are such as 
are due to the fact that in the latter case the protoplasm is 



* "Lehre von der Pflanzenzelle," p^. 30. 



PROTOPLASM MOVEMENTS. 11 

free to move in any direction, while in the former its move- 
ments are greatly restricted by the surrounding walls. In 
closed cells there are two general kinds of movements — one 
a streaming, the other a mass movement — comparable to the 
streaming and Amoeba movements of the naked cells or pro- 
toplasmic masses. No movement takes place, however (at any 
rate to no great extent), until the vacuoles are quite large. 

12 — The streaming movements occur in the protoplasmic 
strings, bands, and plates which cross or separate the vacu- 
oles, and in the lining layer of protoplasm which invests the 
inner surface of the cell-wall. The motion, in many cases, 
shows the same alternation as in the Myxomycetes, the direc- 
tion of the streaming usually being reversed after the lapse 
of a few minutes. 

The mass-movement in closed cells is not as clearly sepa- 
rated from the streaming as in naked cells. It usually con- 
sists in a sliding or gliding of the protoplasm upon the inner 
surface of the cell-wall, in much the same way as the naked 
Plasmodium of one of the Myxomycetes moves upon the sur- 
face of its support. The limited si3ace in which its move- 
ment must take place in closed cells, and its disposition over 
the whole inner surface of the wall, compel the protoplasm 
to move in opposite directions upon opposite sides of the 
cell. There is thus a kind of rotation of the protoplasm 
when the movement of all its parts is uniform. 

{a) The streaming movements may be studied in the stamen-hairs of 
Tradescantia Vwginica, the stinging hairs of the nettle {Urtica), the 
hairs of Cucurhita, Ecbalium, and Solarium tuberosuin, the styles of 
Zea mats, the easily separated cells of the ripe fruit of Symphoricar- 
pus raeemosus, the young pollen grains of (Enothera, and the paren- 
chyma of succulent monocotyledons — e.g., in the flower peduncles and 
the filaments of Tradescantia. The parenchyma cells of the leaves of 
many trees and of the prothallia of ferns and Equisetums show a net- 
work of hyaline strings in which a streaming may with difficulty be seen. 

Among the lower plants good examples may be found in the hyphae 
of some Saprolegnise, and in the cells of Spirogyra, Closterium, DentU 
cella, and Coscinodiscus. 

(b) In many cases (e.g., in the unfertilized embryo-sac of many 
Phanerogams, in the young endosperm cells, and in the spore-mother- 
cells of Anthoceros Imms) — where the strings and bands resemble those 
in the cases cited above — no movement of the protoplasm is visible, 



10 BOTANY. 

perature of 20° C. to one of 30° C. (G8° to 86° Falir.), withdraws its pseud- 
opodia and ceases its activity in tlie space of five minutes. In an hour 
after the restoration of tlie normal temperature (20° C.) the movements 
begin again. If the temperature is raised to 35° C. (95° Fahr.) the 
organization of tiie plasmodium is destroyed. 

The Plasmodium of Fuligo vmians, Sommf. {^thalium septicum, 
Fr.), when placed in a chamber surrounded by ice, contracts into a 
rounded form and ceases all motion ; upon gradually raising the tem- 
perature again the normal state is resumed. 

{d) In glycerine, a concentrated solution of sugar, a five per cent solu- 
tion of potassium nitrate, or a five per cent solution of sodium chloride, a 
Plasmodium contracts, and becomes rounded and motionless. A sudden 
decrease in the concentration of the solution by which a plasmodium 
is surrounded also results in a stoppage of its movements. A plasmo- 
dium of Didymium serpula, when placed in a one per cent solution 
of potassium nitrate, and allowed time to regain its activity, suddenly 
rounds itself up and stops its movements when the preparation is 
washed out with distilled water ; after the lapse of a few minutes (ten 
to twelve) the activity begins to show itself again, and in half an hour 
the normal state is restored. 

10.— Ciliary Movement. The swimming of swarm-spores, 
spermatozoids, and many other naked protoplasmic bodies, is 
due to the rapid vibratory motion of extremely small whip- 
like extensions of the hyaline portion of the protoplasm. 

Examples of ciliary movement are very common. In some swarm- 
spores, as in those of Vaucheria, the whole surface is covered with short 
cilia ; in others, as in CEdogonium, the cilia form a crown about the hya- 
line anterior extremity ; those of Pandorina and Cladophora, and the 
spermatozoids of Bryophytes and Pteridophytes, have two or more cilia ; 
while the swarm-spores of Myxomycetes have but one. 

The rapidity of the swimming motion produced by cilia is consider- 
able, as shown by measurements made by Hoimeister* in the case of 
swarm-spores, viz. : 

Fuligo mrians {JEthalium septicum). .. .7 to .9 mm. per second. 

Lycogola epidendrum .33 mm. 

CEdogonium vesicatum 15 to .20 mm. " 

Vaucheria sp 10 to. 14 mm." 

1 1 .—The Activity of Protoplasm Enclosed in a Cell- wall. 
The movements of protoplasm in closed cells differ but 
little from those in naked ones ; the differences are such as 
are due to the fact that in the latter case the protoplasm is 



* "Lehre von der Pflanzenzelle," p. 30. 



PliOTOPLASM MOVEMENTS. 11 

free to move in any direction, while in the former its move- 
ments are greatly restricted by the surrounding walls. In 
closed cells there are two general kinds of movements — one 
a streaming, the other a mass movement — comparable to the 
streaming and Amoeba movements of the naked cells or pro- 
toplasmic masses. No movement takes place, however (at any 
rate to no great extent), until the vacuoles are quite large. 

12 — The streaming movements occur in the protoplasmic 
strings, bands, and plates which cross or separate the vacu- 
oles, and in the lining layer of protoplasm which invests the 
inner surface of the cell-walk The motion, in many cases, 
shows the same alternation as in the Myxomycetes, the direc- 
tion of the streaming usually being reversed after the lapse 
of a few minutes. 

The mass-movement in closed cells is not as clearly sepa- 
rated from the streaming as in naked cells. It usually con- 
sists in a sliding or gliding of the protoplasm upon the inner 
surface of the cell-wall, in much the same way as the naked 
Plasmodium of one of the Myxomycetes moves upon the sur- 
face of its support. The limited space in which its move- 
ment must take j)lace in closed cells, and its disposition over 
the whole inner surface of the wall, compel the protoplasm 
to move in opposite directions upon opposite sides of the 
cell. There is thus a kind of rotation of the 23rotoplasm 
when the movement of all its parts is uniform. 

{a) The streaming movements may be studied in the stamen-hairs of 
Tradescantia Virginica, the stinging hairs of the nettle ( Urtica), the 
hairs of Cucurbita, Ecbalium, and Solarium tuberosum, the styles of 
Zea mais, the easily separated cells of the ripe fruit of Symphoricar- 
pus racemosus, the young pollen grains of CE/iothera, and the paren- 
chyma of succulent monocotyledons — e.g., in the flower peduncles and 
the filaments of Tradescantia. The parenchyma cells of the leaves of 
many trees and of the prothallia of ferns and Equisetums show a net- 
work of hyaline strings in which a streaming may with difficulty be seen. 

Among the lower plants good examples may be found in the hyphae 
of some Saprolegnise, and in the cells of Spirogyra, Closterium, Denti- 
cella, and Coscinodisciis. 

(6) In many cases (e.g., in the unfertilized embryo-sac of many 
Phanerogams, in the young endosperm cells, and in the spore-mother- 
oells of Anthoceros loivis) — where the strings and bands resemble those 
in the cases cited above — no movement of the protoplasm is visible, 



14 EOT ANT. 

(/) The passage from the condition in the last examples (the so. 
called circulation of protoplasm) is an easy one to the cases where the 
whole mass of protoplasm moves along the cell-wall as a broad stream, 
passing up one side and down the other (the so-called rotation of pro- 
toplasm). Common and well-known examples of this kind of mass-move- 
ment occur in Chara, Naias, and Vallisneria. It may also (on the 
authority of Meyen) be studied in the root-hairs of many land plants — 
e.g.^ of Impatiens Balsamina, Vicia faba, Ipomoaa purpurea, Cucumis, 
Cucurbita, Ranunculus sceleratus, and Marchantia polymorpha. 

Note. — In the study of the structures treated of in Chapters I to \' 
inclusive, the student will do well to consult a recent laboratory man- 
ual — "Botanical Micro-Chemistry," by V. A. Poulsen (William Tre-^ 
lease, 1884). 



CHAPTER II. 

THE PLANT-CELL. 

13. — In some cases plant protoplasm has no definite or 
constant form. This is its permanent condition in some of 
the lowest plants — e.g., the Myxomycetes. In most other 
lower plants, and in all the higher ones, it has this condition 
only temporarily, if at all. In the great majority of cases, 
however, the protoplasm of which a plant is composed has a 
definite, and, within certain limits, a constant form. It usu- 
ally appears in more or less rounded or cubical masses of 
minute size, and which may or may not be surrounded by a 
cell-wall. In this condition it constitutes the Plant-Cell. 

The undifferentiated protoplasm of the Myxomycetes reminds us of 
the lower Monera among animals. In Bathybius and Protamoeba the 
naked protoplasm of which they are composed has no constant form. 
In Protomyxa we have a few simple transformations which are in every 
respect comparable to those of the Myxomycetes.* In higher animals 
the protoplasm exists in minute and definitely marked masses, termed 
cells, or,corpuscles, and these have been shown to he the exact homo- 
logues of the cells of plants. 

14. — While in young cells provided with a wall the pro- 
toplasm fills the whole cavity, as in A, ¥\g. 2 (p. 3), in 
older ones it never does so, and generally these contain only 
a very small portion of it, as a thin layer covering the inner 
surface of the cell- wall {B and C, Fig. 2). Close examina- 
tion shows that this protoplasmic sac consists of (1) a firmer 
hyaline layer, the ectoplasm, which is in contact with the 



* See farther on this subject in paragraph 222, Chapter XI. For a 
short account of these interesting animal forms mentioned above, the 
student is referred to Dr. Packard's " Zoology for Students and Gten. 
eral Readers," (p. 18 et seq.) in the series of which the present work 
forms a part, and his " Life-Histories of Animals," where are also given 
niunerous references to fuller accounts. 



16 BOTANY, 

cell-wall ; and (2) within this a less dense granular one, the 
endoplasm ; the two layers are, however, not separated from 
each other by any sharp line of demarkation.* 

When the endoplasm attains a considerable thickness it becomes dif- 
ferentiated into an external denser layer and an internal less dense 
one. Often one of these layers may be found to be in motion while the 
other is at rest.f 

15. — There may almost always be seen in plant-cells bands 
or strings of protoplasm which lie in or between the vacu- 
oles (Fig. 2, B), They are at first thickish plates which 
separate vacuoles, but afterward they become narrower as 
the vacuoles enlarge, and at last they disappear entirely. In 
these bands and strings, as previously stated (paragraph 12), 
streaming movements are frequently to be seen. 

16. — Each of the protoplasm masses constituting the cells 
of most plants usually has a portion of its interior substance 
differentiated into a firmer rounded body, the nucleus Its 
normal position is in the centre of the cell ; but it may be 
displaced and pushed aside by the vacuoles, so that in an 
optical section of the cell it may often appear to be in the 
margin. The structure of the nucleus has been shown to be 
quite complex. There are at least two pretty distinct por- 
tions, viz. : (1) a hyaline substance making up the body of 
the nucleus, to which the' name Achromatin has been given, 
on account of its taking stains less readily, and (2) a granu- 
lar substance which is often in the form of rods or threads, 
named Chromatin on account of its freely absorbing stains. 
The nucleus commonly contains one or more distinct rounded 
granules, the nucleoli (Fig. 2, A, B, C). 

17. — Cells are of very varying sizes. They differ in dif- 
ferent plants, and also in the different parts of the same 
plant. In but few cases, however, are they of great size, by 
far the larger number being microscopic. The most striking 



* These two layers were first described by Pringsheim in his *' Theorie 
der Pflanzenzelle," 1854. 

f Cf. Strasburger, " Studien liber Protoplasma," 1876; and Qr, Jr, 
Mic. Science, 1877, pp. 124-132. 



THE PLANT-CELL. 



17 



examples of large cells are found in the Thallophytes ; Nitella, 
for example, has cells 50 mm. (2 inches) long, and 1 mm. 
(.04 inch) thick. According to Von Mohl, the bast-cells 
of a species of palm {Astrocaryum) are from 3.6 to 5.6 mm. 
(.13 to .21 inch) in length. For ordinary plants the average 
size of the cells may be given as from .1 to .02 mm. (.004 to 
.0008 inch). From this average size the dimensions of cells 
decrease to exceedingly small magnitudes. In the Yea-t 
Plant [Saccharomyces cerevisice) the cells are about .008 mm. 
(.0003 inch) in diameter. The cells of Bacterhmi termo are 
from .0021 to .0028 mm. long and from .0028 to .0005 mm. 
broad (.0001-.00008 by .00008-.00002 inch). 

The following table, taken from Hofmeister's " Lelire von der Pflan- 
zenzelle," is useful as showing how the dimensions of similar cells 
vary in different plants : 

Table of Dimensions of Various Kinds of Cells of Woody 

Plants. 

(In decimals of a millimetre,) 



Cambium-cells, average length 

Vessel-like wood-cells, average length 

Bast-like wood-cells, average length 

Vessel -cells of the wood, average length 

Latticed cells of young secondary bark, aver- 
age length 

Bast-cells of young secondary bark, average 
length 

Cells of medullary ray in the cambium ring, 
maximum length in tangential section 

Do., do., maximum width in tangential sec- 
tion 

Cells of medullary ray in the young wood, 
average length in tangential section 

Do., do., average width in tangential section. 

Cells of medullary ray in the young secon- 
dary^ bark, average length in tangential 
section 

Do., do., average width in tangential sec- 
tion 



^1 




5|. 


i '^ s 


< 

la 

^ o 

2 AM 

3 2.S 


^ O 

li 
>^ 

^ iz; S 


M 


fe"^ 


O* 


> 


o 


1-3 


.201 


.413 


.528 


.339 


.786 


1.511 


.308 






1.179 




2.020 


.301 


.588 


.712 




1,819 




.205 


.404 




.eis 




.... 


.212 


.520 


.... 






.... 


.798 




1.292 


.403 


1.152 


2.183 


.321 


.437 


.178 


.338 


.466 


.049 


.041 


.076 


.011 


.017 


.056 


.014 


.376 


.519 


.285 


.567 


.630 


.095 


043 


.077 


.019 


.037 


.075 


.019 


.342 


.912 


.468 


.504 


.744 


.172 


.057 


.066 


031 


.076 


.075 


.026 



18 BOTANY. 

18. — Every free mass of protoplasm tends to assume a 
spherical form. The free cells of the unicellular water plants 
are generally more or less rounded, as are also the floating 
spores of most aquatic Thallophytes. In jjlants comjoosed of 
masses of cells their mutual pressure gives them an angular 
outline. Where the pressure is slight the cells. depart but 
little from the spherical shape, but as it becomes greater 
they assume more and more the form of bodies bounded by 
planes. If the diameters of the individual cells are equal 
and the development of the mass of cells has been uniform 
in every direction, we may have regular cubes, or twelve-sided 
bodies, i.e., dodecahedra. It is rarely the case, however, 
that the cells have a perfectly regular form. Even when 
their diameters are approximately equal, they are generally 
so much distorted that they are best described as irregular 
polyhedra. 

19 — It much more frequently happens that cells grow 
more in some directions than in others, and thus give rise 
to elongated and many irregular forms. In many of the 
Thallophytes the long filaments composing the plants 
are made up of elongated cylindrical cells placed end to 
end ; while in others the cells are repeatedly and irregularly 
branched. 

In higher plants many elongated cells occur, but here, 
by pressure, they generally become prismatic in cross-section. 

{a) Many forms of cells have been enumerated, but tliey may all be 
arranged under the two principal kinds indicated above, viz., the 
short, and the elongated. As will be more fully shown hereafter, the 
various kinds of short cells constitute what is called Parenchyma; 
hence the cells themselves are termed Parenchymatous cells, or Paren- 
chyma cells. Similarly, certain kinds of the elongated cells constitute 
Prosenchyma, and hence such are termed Prosenchymatous cells, or 
Prosenchyma cells. While it is impossible to draw an exact line be- 
tween parenchymatous and prosenchymatous forms, yet the terms are 
valuable, and are in constant use to indicate the general form, 

(&) Duchartre* has made an excellent classification of the prin- 

* In his Elements de Botanique," second edition, a large and 
valuable work, which the student niay profitably consult. 



THE PLANT-CELL. 



19 



cipal forms of cells, wliicli is given below in a slightly modified 
form: 



Cell globular or 
ovoid, in section 
round or oval .... Spheroidal. 

Cell polyhedral. Polyhedral 

Cell a parallelo- 
pipedon, in section 
rectangular Cuboidal. 

Cell tabular, 
with an elongated 
rectangular s e c - 
I tion Tabular. 



Cell short 

yPar enchyma- 

tous). 



Outline smooth, 
or without promi- 
nences. 



Cell ramose, 
having short and 
irregular projec- 
_ With prominences. J tions Ramose. 



Cell star-shap- 
ed, having long 
projections w^hich 
(^ are more regular. . 



Stellate. 



Cell elongated. 



Cell cylindrical, with its ends at 
right angles to its axis, or but little 
inclined Cylindrical. 

Cell prismatic, with its ends at 
right angles to its axis, or but little 
inclined Prismatic. 

Cell fusiform [cylindrical or pris- 
matic], with its ends oblique and 

pointed Fusiform 

{Prosenchyma 
tous). 



20. — When one or more sides of a cell are not in contact 
with other cells, as is the case with those cells which com- 
pose the surface of plants, the free sides are generally con- 
vex, and they often become more or less prolonged, sometimes 
in a curious way. The velvety appearance of the petals of 
many plants is due to such prolongations of the free sides of 
the surface cells (Fig. 8). Of a somewhat similar nature are 
the tubular extensions of the surface cells of young roots — • 
the root-hairs. And here we may also place the curious star* 
shaped cells which project into the intercellular spaces in the 
interior of the stem of the water lily (Fig. 9), and those 
which compose the pith of certain rushes (Fig. 9^). 

2 1 . — In the unicellular plants each cell is an independent 



30 



BOTANY. 



organism ; it absorbs nourishment, assimilates, grows, and 
reproduces its kind. In the higher plants, although this 
independence is not so evident, it still 
exists in a considerable degree. Here 
each cell is an individual in a commu- 
nity ; but it still has a life-history of its 
own, a formation (genesis), growth, ma- 
turity, and death. It is the unit in the 
plant. Upon its changes in size, form, 
and structure depend the volume, shape, 
thf fpSeTmil^t^lff ^Itai ^""^ structural characters of the plant 
of apansy (Fioto t?icoior) and all its parts. It is thus the Morpho- 




showing prolongations of . . 

the free (upper) sides of tile loOlCal Unit 01 the plant. 

cells. Mag. — After Du- ^ ^^ a - 1 in 

ehartre. 22. — As the wliole structure 01 



the 



plant is an aggregation of cells, so the functions of th( 
whole;, or of any part of a plant are but the sum or result 




Fig. 9A. 



Fig. 9. 

Fig. 9.— A cross-section through the petiole of Nuphar advena ; s, s, star-shaped 
cells projecting into the intercellular spaces i, i ; g, a, reduced fibro-vascular bundle. 
Magnified.— After Sachs. 

Fig. 9&. — Stellate cells from the pith of Juncus efusus, magnified.— After Du-' 
ehartre. 

ant of the physiological activities of its individual cells, 
The cell is thus also the Physiological Unit of the plant. 



CHAPTER III. 

THE CELL-WALL. 

23.— In all but the lowest plants the protoplasm of every 
cell surrounds itself sooner or later with a covering or wall 
of cellulose. The substance of the cell-wall is a secretion 
from the protoplasm. Cellulose, as such, does not exist in 
the protoplasm ; it is formed on the surface when the wall is 
made. On its first appearance the wall is an extremely thin 
membrane, but by subsequent additions it may acquire vary- 
ing degrees of thickncs;-. The cell-wall forms a complete 
covering for the protoplasm ; there are at first no openings 
in it, at least none that are visible ; later in the life of the 
cell pores are formed in the wall in some cases, while quite 
frequently in dead cell-walls there are large perforations of 
various sizes and shapes. 

{a) Cellulose is related chemically to starch and sugar. Its composi- 
tion is Ci2 H20 Oio. It is tough and elastic. It is but slig-htly soluble 
in dilute acids and alkalies, and not at all in water and alcohol. In 
water, however, it swells up from imbibing some of the liquid, but it 
shrinks again in bulk when dried. 

(6) Tests. — 1. If cellulose is treated with dilute sulphuric acid, and 
shortly afterward with a weak solution of iodine, it is colored blue. 

2. Treated with Schultz's Solution it assumes a blue color. 

(c) In the Myxomycetes, if the large mass of protoplasm composing a 
plant is somewhat dried, it separates itself into smaller masses, which 
surround themselves with a cell-wall. Upon applying sulphuric acid 
and iodine, the characteristic blue color of cellulose appears, showing 
that the wall is a true wall of cellulose. If, however, any such dried 
mass of protoplasm is subjected to the proper conditions of moisture 
and temperature, the cell-wall is dissolved and absorbed into the proto- 
plasmic mass. Tests applied now utterly fail to show the presence of 
cellulose. These observations prove the truth of the statement that 
cellulose is a secretion, and that it is not contained, as cellulose, in the 
protoplasm. 



22 



BOTANY. 



24. — After tlie formation of the cell-wall it generall_y 
grows, and increases its surface and thickness. Usually the 
surface-growth at first preponderates, afterward that in 
thickness. Neither the one nor the other is uniform over 
all points of the cell-wall, hence each cell during its growth 
may also change its form. As the growth of the cell- wall is 
directly dependent upon the protoplasm, it is clear that it 
can continue only as long as the protoplasm is in contact 

with its inner surface. In the 
growth of the cell- wall the new 
cellulose secreted by the protoplasm 
is deposited between the molecules 
of the membrane already formed. 
When the new molecules are de- 
posited between the previously 
formed ones only in the plane of 
the cell-wall, surface-growth takes 
place ; but when the planes of de- 
position of the new molecules lie at 
right angles to the j)lane of the 
cell-wall, increase in thickness is 
the result ; when the molecules are 
deposited in both planes, the wail 
increases both in surface and thick- 
ness. 

25. — Surface-growth may be 
terminal or intercalary. In the for- 
mer case the growth is greatest at 
some point on the surface, decreas- 




Fig. 10.— Diagrams to illustrate 
the intercalary growth of CEdogo- 
iiium. A, internal ring of cellu- 
lose secreted at /; B, showing 
the way in which/by the horiz' n- 
tal splitting of ihe ring, the cell is 
oioiigated ; z, the new portion of 
the wall formed by the splitting 
and extension of the ring/ in A ; 
C, c, the so-called cap, formed by 

several succei^sive extensions of • • • x •- ii ;.]Ap^ my^ 

the cells by intercalary growth.— ^^S ^^ mienSlW OU au SlOCS. XUC 

point thus comes to pro- 



lyl oditied from Sachs. 



growing 

ject as a point or knob, or it becomes the end of a cylindri- 
cal sac. If several points of growth occur in a cell it may 
become star-shaped, and by a continuation of the process 
repeatedly branched. The typical form of intercalary 
growth takes place in definite belts which surround the cell, 
as is seen in (Edogonium (Fig. 10). The growth of the 
whole of the side wall of a cylindrical cell, as in Spirogyra, 
is also a form of intercalary growth. 



THE GELL-WALL. 



33 




26. — Growth in thickness of the wall produces changes 
m the cell of even greater importance than growth in sur- 
face. While surface-growth has but little to do with the 
determination of the functions of the cell, the thickening of 
its wall generally results in a 
change in function, or an entire 
suspension of all physiological 
activities. Cells with extremely 
thin Avails are most active ; only 
such can take part m growth. 
(See Chap. XI.) Nutrition and 
assimilation are confined to cells 
whose walls have but slight thick- 
ness. Cells with moderately thick 
walls may be used as storehouses 
for food ; starch, for example, is 
frequently found in such cells. But as the walls attain great 
thickness the protoplasm loses all activity save that neces- 
sary to the secretion of cellulose. 

27. — The thickening generally produces certain markings 
or sculpturings in the shape of projecting points, ridges, 
bands, etc., which on the one hand are on 
the outside of the wall, while on the 
other they are on the inside. In some 
pollen grains and spores we have the best 
examples of external markings. Here, in 
some cases, certain isolated points in the 
cell-wall become strongly thickened, g-iv- 
ing rise to spines or prickles (Fig. 11). 



Fig. 11.— Pollen grain of Lavatera 
trimestris, covered witu prickles. 
X 200.- After Ducharire. 




Fig. 12, —Ripe pollen 
grain of Cichorium Inly- 

t^^.t^t^Ttt^'&^^Sx In otl^er cases the thickening is in cer- 

is furbished with ridge- tain bands, which may rise into hidi 

nke thickenings united ^ J o 

into a network. Each of walls, as in Fiff. 12. External markings 

these bears thickenings, -' o o 



.vhich project still more, occur Only upon cclls whicli are free, or 

in the form of spines ar- . t i , ^ • '±1 j_i 

slight contact with one another "' 



spines 
ranged like a comb.— After m 

with other cells. 



or 



28. — Internal markings are of essentially the same kind 
as the external, although of greater variety. When the 
secretion of new cellulose is greatest at isolated points, knobs 
and projections of various kinds are the result. It more 



24: 



BOTANY. 



frequently happens, however, that the thickening is in bands 
of greater or less width, occasionally extending over nearly 
the whole inner surface. 

One of the simplest cases is represented in Fig. 13, where 
new material has been added to all parts of the wall ex- 





FiG. 13B. Fig. 13^. Fig. 14. 

Fig. 13. — J, optical section of a sclerenchyma-cell from beneath tlie epidermis of 
the underground stt-m of Pieris aquilina, isolated by Schulze'i? maceration The 
wall consists of an inner very dense layer, and a central less dense one enclosed 
between two denser ones; these layers are penetrated by pit channels, which are 
seen in the further wall in transverse section. B, a similar cell, more thickened. 
The pits are here long cana's, which are more or less branched, x about 550.— 
After Sachs. 

Fig. 14. — Brown-walled cells in the stem of Pteris aquilina. A, a half cell iso- 
lated and rendered oolo I less by Schulze's maceration. B, a piece more strongly 
magnified (X 550). The fissure-like pits are crossed, i.e.. the fissure is twisted as 
the thickening increases; p, a side view of a fissure appearing as a simple channel, 
since it shows the narrow diameter. C, cross-section; a, boundary lamella; b, c, 
Inner lamellae.— After Sachs. 

cepting in small isolated spots. As the wall thickens around 
these spots, they become at first pits, and finally channels, 

29.— In some cases the pits or channels are simple, 
straight, or slightly bent extensions of the central cell-cav- 
ity ; in others they may be branched, as shown in Fig ISB ; 
in cross-section they may be round, as in Fig. 13 J, or elon- 



THICKENmaS OF THE WALL. 



25 



tliickening 



gated fissures, as in Fig. 14, or of any form intermediate 
between these. Pits with elongated fissures may be twisted, 
giving them, when seen in front view, the appearance of two 
fissures crossing one another (Fig. 14^4, B). 

30. — In the thickening of the cells of the wood of the 
Coniferae bordered pits are formed (Fig. 15). Here large 
round areas of the wall remain thin, and the 
mass arches over them on all 
sides in such a way as to form 
low domes (Fig. 16, i^) ; at the 
top of each dome a small round 
opening is left, and this permits 
free communication between the 
cavity of the cell and the pits 
formed by the dome. This pro- 
cess takes place in exactly the 
same way upon both sides of the 
common wall of contiguous cells 
(Fig. 16, B, t, t, and C). When 
the partition separating opposite 
pits breaks away, as it generally 
does quite soon, the resulting cav- 
ity is doubly convex in shape 
(Fig. 16, E): When a pit of 
this structure is seen nn front 
view, it has the appearance of two pj^ i^__pinus syivestns; longi- 

poripp-nfrip piVpIp*? /'Ficr ^^ i" tudinal radial section through the 
concentric circles (^J^lg. iO, ?, ^ood of a rapidly g owing branch; 

and Fio:. 16, D) ; the outer one c, ^ (umbial wood-cells (tracVieides) ; 

. p ' ,^ ' fl( to e, older wood -cells (rracheides); 

bemff formed by the bottom of ^^ t", t"\ bordered pits, increasing in 

,, ^ ., T ji • 1 ii age ; 5i, large pits wnere ct llsof the 

the pit, and the inner by the medullary rays Ue next to the wood- 

opening at its top. ^^"^- x«5. -After sacta. 

The bordered pits of pines, firs, and otlier Coniferae may be readily 
examined by making a longitudinal radial section. They are not found 
in abundance on the tano-ential surfaces of the cell<5. 

The re?l structure of the bordered pits of the Coniferae was not under- 
stood until quite recently.* Von Mohl, apparently not noticing the 

* Schacht, in 1859 {Botanische ZeiPing, pp. 238, 239), and in a memoir 
in 1860 (" De Maculis in Plantarum Vasis Cellulisque Lignosis"), gave 
the first correct explanation of the structure of bordered pits. 




20 



BOTANY, 




r 



w&. 



thin partition, thought that the lenticular cavity was formed by the 
separation of the walls of the two contiguous cells at that place, and con- 

^ , ^^^ sequently that tliey were 

intercellular. This in- 
terpretation is still given 
in some hooks.* 

31. — While the 
bordered pits of the 
Coniferae are never 
crowded together, in 
the cells of some 
plants they are so 
numerous as to lie 
closely side by side 
(Fig. 17). In such 
case the first thick- 
ening of the wall pre- 
sents itself as a net- 
work of ridges en- 
closing elliptical thin 
23laces. As the thick- 
ening advances the 
ridges increase in 
height, but at first 
not in breadth ; later 
they increase in 
breadth at the top and 
oyerarch the thin 
areas, much as in the 
bordered pits of the 
Coniferse. In this 
case, however, the 
opening at the toj) of 
the pit is an elongat- 
ed slit instead of a 
circle (Fig. 17, A. 
and C, 6'). The thin 




Fig. 16.— Bordered pits of Pinus sylvestris. A, 
traiisverse section of mature wood ; rn, central layer 
of the comn^on wail; t, a mature pit cut through the 
middle ; t'., the same, but in a thicker part of the sec- 
tion, the part of the cavity of the pit seen in perspec- 
tive ; t^', a pit cut through below its openings ; B, 
transverse section through the cambium ; c, cambium ; 
h, very young wood-cells ; t, i, very young bordered 
pits, seen in section ; C, diagram of sectional and lat- 
eral views of a young bordered pit; D, diagram of 
sectional and lateral views of a mature bordered pit ; 
^, section of a mature pit, seen in perspective ; F, 
section of a younger pit seen in perspective. A and 
B X 800.— After Sachs. 



plate separating opposite bordered pits of this kind breaks 

* See Le Maout and Decaisne's '* Traite Generale de Botanique," 1863 
[English edition, 1872] ; Griffith and Heufrey's " Micrographic Die- 



THICKENINGS OF THE WALL. 



27 



away as in the previous case, and so free communication 
between adjacent ceils or vessels is established. 




Fig. 18. 

Fig. 17.— Bordered pits of the thick root of Dahlia tiariabilis. A, front view of a 
piece of the wall of a vessel, seen from without ; B, transverse section of the same 
(horizontal, and at right angles to the paper) ; C, lougiturlinal section of A (vertical, 
and at right angles to the paper) ; q, septum ; a, the original thin thickening- ridge ; 
6, the expanded part of the th ckeninij masses, formed later and overarching the pit ; 
t, the fissure through which the cavity of the pit communicates with the cell cavity ; 
at ct and i3 the corresponding front view is appended, in order to make the trans- 
Terse and longitudinal sections more clear. x 800.— After Sachs. 

Fig. 18.— Scalariform thickening of the walls of a vessel from the underground 
stem of Pferis afpdUna. A, half-vessel, isol ited by Schulze's maceration ; B to D, 
pieces obtained from stemn hardei ed in absolute alcohol ; B,a, partly diagrammatic 
view of a vertical section of the wall, seen from within ; c, c, plan of section ; c?, 
opening to pit ; 6', front view of young wall of a vessel ; s, unthickened portion of 
wall; w, thickening-ridge; Z>, vertical section of C," £", section of wall in a place 
where a vessel adjoins a succulent cell p ; the thickening-ridges (g) are only on 
one side. X 800.— After Sachs. 

tionary," third edition, 1874; Carpenter's " The Microscope," fifth edi- 
tion, 1874 



28 



BOTANY. 



32. — The passage from tlie mode of thickening just de- 
scribed to the scalariform manner (Fig. 18) is an easy one. 
Here each longitudinal angle of the cell or vessel is thickened, 
and from these thickened angles ridges run right and left, 
from one to the other (Fig. 18, C, v). The after growth 
of the ridges is essentially the same as in the case of crowded 
pits ; in fact, the pits here are simj^ly greatly elongated and 
crowded bordered pits. Eventually the narrow plates be- 
tween the thickened ridges disappear, as in the other cases. 
Examples of scalariform thickening arc common, especially 
in the ferns. 

33. — The development of rings (Fig. 19, v) is nearly like 



that of the scalariform thickening. 



Instead, however, of 




Fig. 19.— Longitudinal section of a portion of the stem of Impatiens Baltamma. 
V, annular vessel, v^, a vessel with thickenings which are partly spiral and partly an- 
nular ; v'^, v'", v""^ several varieties of spiral vessels ; v'""^ a reticulated vessel.— 
After Duchartre. 

the ridges being short, they extend entirely around the inner 
surface of the wall. The transition from rings to spirals is 
a simple one, the thickening taking place in a spiral line, 
instead of in one passing directly around the wall (Fig. 19, 
v'\ v'"). Transitional forms are frequently found (Fig. 19, 
v'), and many modifications and irregularities occur — e.g., 
in the figure at v'"" is the form known as the reticulated. 

34. — In all the foregoing cases the marking of the wall 
has been general ; there are some cases, however, where it 
is localized. A good example of this is in the formation of 
the pits of sieve-cells (Fig. 20). The horizontal walls, and 
also areas upon the longitudinal ones, become thickened 
reticulately, leaving rather large thin areas, as shown in 
Fig. 20, q. q. After a while the thin areas become absorbed. 



THIGKENIN08 OF THE WALL. 



29 



allowing the protoplasm of contiguous cells to become struc- 
turally united. The sieve- like appearance of these modified 
portions of the wall give to the cells their name of sieve-cells. 

35.— The collen- 
chyma cells which 
are frequently found 
beneath the epider- 
mis of the succulent 
parts of h i g h e r 
plants afford an- 
other instance of 
localized thicken- 
ing. Here only the 
angles of the cells 
become thickened, 
leaving broad por- 
tions of the wall un- 
modified (Fig. 21). 

{a) Examples of tlie 
uniform thickening of 
the cell-wall may be 
obtained for study by 
making thin sections of 
the hard parts of many 
nuts and seeds (Figs. 58 
to 61) ; in many of these 
more or less complex 
channels may be found. 
Bordered pits are best 
studied in longitudinal 
sections of the young 
wood of the pines, firs, Fig. 20.— Young sieve tubes of Cucur'bUa pepo The 
^fr> on^ tlio ^rr^w^^rl drawing made from Specimens vvhich, bv having lain a 
etc., ana me crowaea ion,, time m absolute alcohol, have allowed the pr 




pits in the 
most other 
gams. 



stems 
Phanero- 



produc- 
of tioiV of extremely cleai" sections; q, transverse view of 
sieve-like septa ; si, sieve plate on side wall ; x, thin- 
ner parts of the longitudinal wall ; I, the same seen in 
Longitudinal section ; ps, contracted protoplasmic contents (lifted 
, off at s/? from the transverse septum, still in contact 

sections ot the stems of at si) ; 2, parenchyma-cells between sieve-tubes, x 550. 
most annuals will yield —After Sachs. 

good examples of ringed, spiral, and reticulated thickening. The 
stems of the Cucurbitacese (Pumpkin, Squash, Gourd, etc.) furnish fine 
examples of sieve cells and collenchyma. 

{b) In this place miv he mentioned the curious and sometimes puz- 



30 



BOTANY. 



zling liernioid protrusions to be met with in some plants. When the 
surrounding cells are very active, it sometimes happens that the thin 
membrane which closes up a pit grows and is pushed through into 




Fig. 21. 

the vessel, as at t 
in the lower fig- 
ure (Fig. 21a), 
where th repre- 
sents the thicken- 
ed portion of the 
wall, and ica the 
thin portion clos- 
ing the pits. Oc- 
casionally many 
such protrusions 
enter the vessel, as 
in a in the upper 
figure ; if these be- 
come large they 
may entirely fill 
up the cavity of 
the vessel, as at h, 
where two large 
ones from opposite 
sides have met. 




Fig. 21a, 

Fig. 21. — Collenchyma cells of the Begonia, transverse sec- 
tion of the petiole. 6, epidermis ; cl. collenchyma-celle, with 
thickened angles, v, v ; chl. chlorophyll-bodies ; p, large cell of 
parenchyma, x 550.— After Sachs. 

Fig. 21a.— Hernioid protrusions into the pitted vessels of 
EcJdnocystis lobata : the upper figure magnified 250, and the 
lower 1000.— From drawings by J^ C. Arthur. 



36.— Theories as to the Mode of Thickening. The real 
nature of the process in the growth in surface and thickness 



THICKENINGS OF THE WALL. 31 

of the cell-wall was for a long time not fully understood. 
There have been three prominent theories advanced to ex- 
plain the phenomena observed. They may be briefly stated 
as follows : 

I. Yon Mohl held that ^^ the growth of the cell-membrane 
in thickness arises from a periodical apposition of new mem- 
branes upon the already completely develo^Ded wall.^' * Ac- 
cording to this theor}', the marks of stratification usually seen 
were supposed to be the lines separating the added mem- 
branes. This deposition was supj)osed to proceed from with- 
out inwards ; that is, the newer layers were supposed to be 
placed inside of the jDreyiously existing ones ; on this ac- 
count this has been called the theory of centripetal thicken- 
ing. Until quite recently this has been the preyailing theo- 
ry in English and American books. 

II. Some obseryers, among whom were Hartig and Hart- 
ing, laying great stress upon the external markings, as seen 
in pollen grains, spores, etc., opposed the foregoing theory, 
and propounded one which has been termed the theory of 
centrifugal thickening. According to this theory, ^^the cell- 
membrane increases in thickness in the direction from 
within outwards by the deposition of layers upon the out- 
side of the original membrane." It is thus the exact oppo- 
site of the previous one ; while in the former the outer 
membrane is supposed to be the oldest, in the latter it is the 
inner one. 

III. The theory which now generally prevails is that the 
thickening of the wall is a growth, due to the formation or 
deposition of new molecules between the molecules of the 
original membrane. It is called the theory of intussuscep- 
tion, and was originated by Xageli in 1858. f 

* The student will find a condensed statement of this tlieorj in tlie 
" Principles of the Anatomy and Physiology of the Vegetable Cell," by 
Hugo Von Mohl, translated by Henfrey, 1851. 

f Nageli, " Die Starkekorner," in " Pfiauzenphysiologischen Unter- 
suchungen," 1858. Duchartre claims for Trecul the first suggestion of 
this theory in 1854. The term intussusception as applied to the growth 
of the cell-wall was used long before this ; Sclileiden, in his " Contri- 



32 BOTANY. 

37. — Every part of the living cell-wall appears, from the 
results of Nageli's researches, to be composed of definite 
molecules, which are not in contact, but separated from one 
another by layers of water, termed the Water of Organiza- 
tion. The thickness of these intermolecular layers, and con- 
sequently the amount of water in tlie whole mass of any cell- 
wall, varies in different cells, and even in the same cell. In 
the denser walls, or parts of walls, the water is less ; in those 
which are less dense it is greater. (Fig. 22.) 

Now it is evident that young cell-walls must have rela- 
tively large amounts of water in their substance, and here is 
where we find a growth taking place. Sachs supposes* that 
an aqueous solution derived from the protoplasm penetrates 
by diffusion between the molecules of the cell-wall. This is 
not a solution of protoplasm, but probably some carbohy- 
drate constituent of the protoplasm which is easily trans- 
formed into cellulose. From this nutrient solution there 
may be formed in the spaces filled with water new molecules 
of cellulose, which push aside and separate the previously 
formed ones ; or the previously formed molecules may be 
simply enlarged by the apposition of new matter. 

According to the theory just described, the formation of any projec- 
tion upon the inner surface of the cell-wall is not by the superficial 
deposition of molecules upon any definite area of the surface of the 
wall, but by the abundant and continued deposition of new molecules 
in the wall ; it consequently becomes thicker at the place of deposi- 
tion ; in this thickened portion still more molecules are deposited, and 
the thickness is further increased, and so on. In the same way projec- 
tions are formed upon the outside of the wall by a slow internal growth. 

38.— Stratification of the Wall. During the increase of 
the cell-wall in thickness, an appearance of stratification 
arises in it (Fig. 23). A cell-wall in which this is strongly 
developed appears to be made up of concentric layers, and 
this no doubt gave rise to the two theories before men- 

butions to Phytogenesis," 1838, makes use of the word, but it may be 
doubted whether he or Trecul gave it exactly the meaning we now do. 
* "Lehrbuch," fourth edition, and the English translation of the 
third edition (" Text-Book of Botany "), Books I. and III. 



STRATIFICATION OF TEE WALL. 



33 




tioned, in which the thickening was supposed to be due to 
the successive deposition of layers, either inside or outside of 
the original wall. It is now known that stratification is due 
to a subsequent 
change in the 
amount of water 
of organization 
present in partic- 
ular parts of the 
wall. When seen 
with the micro- 
scope, those layers 
which contain the 
most water, and 

,, .-, Fig. 22.— Diagrammatic figure to illustrate Nageli's tii '- 

consequently tne ory of the molecular structure of the cell-wall ; m, m, '", 

1 f r.Qn Irwon qt«q the Crystal molecules ;*{;.?(;, w, the layers of Water which 

least CeiiUiOSe, are separate the molecules. The water layers are representc I 

loQQ cfT-mTo-l-tr vn as very thin : thev are frequently much thicker in propor- 

leSS fetroilgiy it- tion to the diameters of the molecules. (Note.— It must 

fractive than ^® home in mind that this figure is purely diagrammatic.) 

those which contain less water, or which, in other words^, are 

denser. 

39. Striation. — In many cases there is also a similar sepa- 
ration into more watery and less watery 
layers at right angles to those just 
mentioned. There may be one system 
of such differentiation, giving rise to a 
transverse striation, which may be an- 
nular (Fig. 24, c, d, e) or spiral (a, t) ; 
or there may be two systems, and then 
the wall appears to be crossed by two- 
sets of spirals which run in opposite 
directions around the cell. 




Mg. 23.— Transverse sec- 
tion of a ba'-t fibre of the 
thickened root of Dahlia 
variabilis ; I, the cavity ; 
K, pit channels which pen- 
etrate the stratification'; 
sp, a crack by which an in- 
ner system of layers has 
become separated, x 800. 
—After Sachs. 



Good examples of stratification may be found 
in the pith-cells of the root of the dahlia, and 
in the epidermal cells of most thick leaves ; and 
of striation in the bast-cells of tli3 periwinkle 
( Vinca major), and the wood of the Douglas 
Spruce {Tsuga Bouglasii). In many cases it is necessary to treat the 
specimens with such acids (e.^., sulphuric acid) or alkalies (e^., caus- 
tic potash) as will produce swelling. 



34 



BOTAN^ 



40.— Formation of Chemically Different Layers. A still 
further differentiation may take place in the thickened wall, 
by which it comes to be made up of layers which differ 
cliemically from one another. This is brought about bj 
the subsequent infiltration of diverse materials into different 
layers. In some cases the chemical 
change is accompanied by so great a 
physical change that the wall sepa- 
rates readily into two or more plates.* 
Thus, in pollen-cells, the original wall 
is usually differentiated into two wide- 
ly differing i^lates : (1) an outer thick 
cuticularized covering (the extine), 
and (2) a thin inner membrane (the 
intine) ; the inner plate is shown by 
tests to be composed of pure cellulose, 
while the outer one is generally so 
filled with other materials as to hide 
completely the cellulose. 

A similar differentiation of the wall 
takes place in certain spores, and in 
such case the outer plate is called the 
exospore (or epispore), and the inner 
one the endospore (see C, D, E, F, 
Eig. 180, p. 262). 

The outer walls of the epidermal 
cells of many plants show a remark- 
able separation into one or more 
plates, the outermost of which is 
highly cuticularized. In some cases, 
as in the cabbage, for example, this 
outer plate may easily be separated as 
a continuous pellicle — the so-called 
cuticle. 

Wood-cells frequently show a well- 
marked separation into plates. This may be seen in Pinus 
sylvestris (Fig. 16, p. 26), where there are three such 




Fig. 24. — Striation of the 
bast fibres of Hoya carnosa ; 
a and b, crossed annular stri- 
ation ; c, d, e, varieties of sim- 
ple annular striation.— After 
Sachs. 



* Thosparetlie ' 

lisli edit . ]i .f his 



Scbalen " of Sachs, translated " Shells " in the Eng- 
'Lehrbuch." 



DIFFERENT LAYERS IN THE WALL. 35 

plates, yiz., a thin inner one {%), a thicker middle one {z)^ 
and a thin outer one [m). The latter is apparently common 
to the two contiguous cells, and is the "primary cell-wall" 
of some authors and the 'intercellular substance" of others. 

The deportment of these layers on the application of reagents is 
interesting. 

1. On treatment with a solution of iodine the outer and middle plates 
turn yellow. 

3. On treatment with iodine and sulphuric acid the outer and middle 
plates turn yellow and the inner one blue. 

3. On treatment with concentrated sulphuric acid the inner and 
middle plates are dissolved, while the outer remains. 

4. On boiling in nitric acid with potassium chlorate the outer plate 
is dissolved, while the middle and inner are not. By this latter process, 
called " Schulze's Maceration," the cells may be isolated, but it must 
be borne in mind that such isolated cells have lost by solution their 
outer plate. 

41. — In some cases the differentiation is of such a nature 
that one or more plates become converted into mucilage in 
water. In the dry state the mucilaginous portions are hard 
and cartilaginous. Examples of the change of the outer plates 
into mucilage are common in the Fucav.3ae, and of a sim- 
ilar change of the inner ones in the seeds of flax and quince.* 

42. — Incombustible Substances, as silica and lime, are 
frequently deposited between the molecules of cellulose in 
the wall. Cell-walls which are filled with considerable quan- 
tities of these substances, upon burning, leave ash-skeletons, 
which retain the form and markings of the cell. The Di- 
atoms furnish excellent examples of highly silicified walls. 
Silica is abundant also in the epidermal cells of grasses 
and scouring-rushes {Equisetacece). 

Lime-skeletons may be obtained by the combustion of thin slices of 
the tissues of many plants upon glass or platinum-foil. The vessels of 
Cucurhita Pepo yield (according to Sachs) beautiful skeletons under this 
treatment, 

Silica-skeletons may be obtained by first soaking the tissue in nitric 
or hydrochloric acid and then burning, or by burning (upon platinum- 
foil) in a drop of sulphuric acid. 

* Sachs attempts to reduce the chemical differentiations of the cell- 
wall to three categories, viz., Cuticularizing, Lignification, and Conver- 
sion into Mucilage. 



CHAPTER IV. 

THE FOEMATION OF NEW CELLS. 

43. — There are two essentially different ways in which 
cells originate, viz., (1) by the division of a protoplasmic 
body into two or more bodies ; (2) by the union of two or 
more protoplasmic bodies. 

44. — Cell-Formation by Division. The simplest cases of 
the formation of cells by division occur in the Myxomy- 
cetes. The swarm-spores {a, Fig 25), which are naked masses 
of freely moving protoplasm, first lose their nuclei (as in l), 
and then become constricted (as at c) ; the constriction 
deepens, and finally divides each mass 
into two parts {d, e,f). 

45, — This may be taken as the 
type of cell-formation by division, 
and in no case does it differ in any 
essential particular from this. Most 
plant-cells, however, are surrounded 
by a wall, whose deportment during 
division enables us to distinguish two 

begun ;rf,.,/, completion of "^^^^ ^r Icss Well-marked modes of 
theprocess.-AfterDeBary. ccll-formation by divisiou. On the 
one hand the wall divides as well as the protoplasm (Fissioji), 
while on the other the wall takes no part in the division, and 
it is only the protoplasm which divides (Liternal Cell-For- 
mation). 

46. — The best examples of Fission are to be seen in those 
unicellular plants which have been frequently described 
iinder the name of Protococcus.'^ ^^The cell elongates and 
the protoplasm divides into two across its longer axis, and 




•Division of the 
swarm-spores of Chondrioder- 
ma difforme ; a, with nucleus ; 
&, nucleus dissolved ; c. two 
nuclei, division of protoplasm 



^See "Huxley and Martin's Biology," Chap. II, 



CELL FORMATION BY DIVISION. 3T 

then a partition is formed subdividing the sac ; the halves 
either separate at once and each rounds itself off and becomes 
an independent cell, or one or both halves again divide in a 
similar way before they separate, and so three or four new 
cells are produced." 

47. — In many of the filamentous Thallophytes a similar fis- 
sion takes place, but in these the cells do not immediately sepa- 
rate from one another after their formation. Thus, in JVostoc 
and Oscillatoria (Fig. 26) the cells do not differ in any essen- 
tial way as to their formation from those which constitute 
Protococcus. In JVostoc after fission the cells round them- 
selves up and retain but a slight and easily separable connec- 
tion with one another ; in 
Oscillatoria, on the con- 
trary, the cells remain cy- 
lindricaland are less read- ^ ^ 

ily separable. ^^fea^^ays^a^Kstefefeii^y ^fefe^itefea^ 

48. — In Spirogyra (Fig. Fig. 26.—^, filament of Nostoc; B, filament 
36, p. 45) new cells f omi "' ^^^^'^"^^^'^- X SOO.-After Praml. 

by the partition of old ones. The protoplasmic sac infolds all 
around the middle of the old cell which is cylindrical m 
shape ; into the circular channel thus formed the cell-wall 
extends, appearing at first as a narrow projection from the 
original wall, but becoming broader and broader, until it 
forms a complete partition. When the new cells have 
elongated by intercalary growth the process of fission may be 
repeated, and so on.* 

49. — The cells which make up the greater part of the 
tissues of the higher plants are formed by fission. In the 
apical cells of Equisetum we find a curious regularity in the 

* The student is referred to Saclis' " Text-Book," pp. 17-18, for a further 
description of this process in Spirogyra ; and to Von Mohl's " Anatomy 
and Physiology of the Vegetable Cell," pp. 50-51, for a description of tlie 
similar fission of Gladophora glomerata {Conferva glomerata, Linn.). Von 
Mohl's description, which was the result of the first accurate investitra- 
tionof cell-formation, is erroneous in tliis— that he supposes that during 
the process, to quote his words, " a cellulose membrane is deposited all 
over the outside of the primordial utricle" of the whole cell, and that 
it is a portion of this new membrane which forms the partition. 



38 



BOTANY. 



division. The triangular apical cells of the growing stems 
divide repeatedly in the manner shown in the diagram (Fig. 
27). Here the cell ABC, bounded by the heavy black 




Fig. 27. — Diagram to show mode of fission of the apical cell, as seen from above. 
/, the cell A, B, C, divided by the partition 1 ; //, the same cell with a second par- 
tition, 2 ; ///, the same cell with a third partition, 3. 

lines, is first divided into two unequal portions by the parti- 
tion 1, 1. ; next the larger portion of the divided cell is again 

divided by the partition 2, II. ; 
later, a third partition (3, III.) 
is formed, and so on. It is no- 
ticeable that in this case the 
partition always forms parallel 
to the oldest wall of the divid- 
ing cell. By continued growth 
the apical cell retains, despite 
its repeated divisions, its origi- 
nal dimensions. 

50. — The growing cells of the 
stem of the English bean ( Yicia 
faha) furnish a good illustration 
of fission in the highest plants. 
In this case, and in many 
other, if not all. Dicotyledons, 
the division takes place directly 
fTg..28.-Meri8tem-ceiis of the stem through the centrally placed 

of Baa/a6a, m process of fission ; m » J r 

the cells a, a, the process is in its nuclCUS ia, Hlff. 28). Alter the 

earlier stage ; at 6 it is completed. X„ ,-pri n i 

300.— After Pranti. lormatio*! 01 the ncw wall each 

new nucleus ndoves away and occupies a position on the 
opposite side of the cell from where it was formed (as at h 
and h). 




CELL FORMATION BY DIVISION, 39 

ia) The foregoing must suffice as examples of Fission. It occurs 
throughout the vegetable kingdom and may be regarded as the great 
means by which cells are multiplied. 

(&) The cambium zone of Dicotyledons may be examined very profit- 
ably by the student. If a thin cross-section of a stem be soaked for a 
short time in a carmine solution, the protoplasm of the cambium zone 
will be colored, and the newly formed partitions made thus more 
distinct. 

(c) The ends of young roots are valuable for study ; longitudinal sec- 
tions of these should be made, and treated as in the previous case. 

{d) Another interesting study of a special kind of fission may be 
taken up in an examination of the development of stomata. (See p. 99.) 

(e) That slight variation of fission, which has sometimes been called 
budding, may be very easily studied in the Yeast Plant {Saccliai'omyces 
cerevisice).* The conidia, stylospores, and basidiospores of many fungi, 
which are more difficult to study, are 
very instructive examples of this va- 
riety of fission. Conidia may be 
studied in Cystopus ; stylospores in 
the Red Rust of the grasses (the so- 
called uredo-stage of Puccinia gram- 
inis) ; and basidiospores in young 
toadstools (Agaricus). 

1^1 Tba VoQQf Plcmf /' <^/^,/. Fig. 29.— TheYeasfPlant, Sacckaro- 

ox. xiit; _Lt;ci&u i iciuu ykjuo- myces cerevzsice. a, rounded cells 

charomyces cerevisim) inrmshes i'o':XgTZlZ% f, ^oToft'^ 
a yery simple example of Inter- J^st S :X.l!!^hn f'p?eTo" 

nal Cell -Formation. Under carrot four cells forming in the inte- 
rior of the parent cell ; d, the four 
certain conditions tlie cells 2T0W danghter-cells ; a and & x 400, c and d 
, • ; 1 n X 750,— After Reets. 

to a larger size than usual ; 

their protoplasmic contents divide into, generally, four 
parts (two to four, according to Sachs), each of which 
rounds itself up and secretes a wall of cellulose on its sur- 
face (Fig. 29, c, d). Cells which divide in this way are called 
mother- cells, and the new ones formed from them daughter- 
cells. In the Yeast Plant after the daughter-cells are fully 
formed the dead wall of the mother-cell breaks up. 

52. — The terminal cells of Achhja (one of the Sapro- 
legniacecB) form large numbers of daughter-cells by the 
breaking up of the protoplasm, as shown in Fig. 30, v4. 
When the daughter-cells escape they become rounded {B,a); 




See " Huxley and Martin's Biology," Chap. I. 



40 



BOTANT. 



after a little while they break their cellulose walls and be- 
come naked motile cells (zoospores) {B, e). 

53. — As the formation of the spores of Bryophytes and 
Pteridophytes, and of the pollen- 
cells in Phanerogams, is essen- 
tially alike, we may take as an 
examj^le the formation of the 
spores of a fern (Fig. 31). The 
nucleus of the mother-cell first 
disappears, and two new nuclei 
arise (I., 11. , III.) ; between the 
nuclei may be seen a line indicat- 
ing the separation of the proto- 
plasmic mass into two halves. 
Next the nucleus in each half is 
absorbed and replaced by two, 
between which a separation of the 
l^rotoplasm soon takes place (IVc, 
v.), thus dividing the cell into 
four equal j)arts, which are at 
first angular, but soon rounded 
and enclosed in cell-w^alls (VI., 
VII., VIIL, IX.). 

54. — In the foregoing cases the 
whole of the protoplasm of the 
mother-cell is used in the forma- 
tion of the daughter-cells. There 
are some cases, however, in which 
only a part of the protoplasm is 
used. One of the best known is 
in the formation of ascospores. 
Plere the mother-cells are usually 
at a the dau-htpr-ceiis have just i^rsre and cloup^ated (Fig. 32, a, 

escaped ; o, the thm cellulose walls o o \ o ^ 7 

of the daushter-ceiis. from which J c) I the nuclcus disappears, and 

the contents have escaped as motile ,^ , -, -, - l^ 

cells (zoospores), e ,• c, a young lat- the protoplasm condeuscs in the 

eral branch. X 550.— After Sachs. ,• <. .t ,i m 

upper portion oi the mother-cell ; 
in some cases (not in the species figured) nuclei appear, and 
about these portions of the protoplasm gather to form the 
ascospores ; in other cases (Fig. 32) the protoplasm condenses 




Fig. 30.— Terminal cells of Achlya. 
A, still closed, but with the proto- 
plasm in process of division ; B, the 
daughter-ctlls escaping through a 
rent in the wall of tue mother-cell : 



CELL FORMATION BY DIVISION. 



41 



about certain points without tlie previous formation of nu- 
clei [d, e). In either case firm walls are secreted about the 
spores while yet in the mother-cell and surrounded by the 
unused part of its protoplasm. 

55. — The most striking example of this variety of internal 
cell-formation is to be found in the development of the 
endosperm cells in the embryo sac of Phanerogams. The 
protoplasm which occupies the cavity of the embryo sac pre- 
sents here and there points of condensation or concentration, 
which in a little time become as many nuclei (Fig. 33, A^ n, n), 
each containing a nucleolus. These nuclei are the first in- 
dications of the form- 
ing cells. Protoplasm 
gathers about the nu- 
clei and forms globu- 
lar or ovoid masses 
(A, a, a), which, after 
acquiring a certain 
size, secrete a thin 
wall of cellulose on 
their surfaces (A,c, c', 
cl). By the continued 
production of new 
cells within the em- 
bryo sac, in this way, 
they finally become 
crowded together into 
a loose tissue, in whose intercellular spaces portions of the 
unconsumed protoplasm yet remain (B). After their forma- 
tion the cells go on increasing in numbers by simple fission 

(a) Saclis f makes a strong distinction between the cases of internal 
cell -formation where, on the one hand, a 2y(^rt only, and, on the other, 

* The student is here referred to the account of the formation of 
endosperm cells in Duchartre's "Elenienis de Botanique," pp. 37-39 ; 
and also to Hofmeister's " Lelire von der Pfianzenzelle," Section 17. 

f " Lehrbuch," 4te auf. In the English translation of the third edi- 
tion all cases of fission are included under the Formation of Cells by 
Division of the Mother-Cell. 




Fig. 31.— Development of the ppores of Aspidium 
filix-mas. /, the spore-mother-ccll, with nucleus ; 
//, the nucleus absorbed ; ///. two nuclei, and the 
division of the protoplasm into two portions ; IV, 
four nuclei ; F. division of the protoplasm into four 
portions ; F/, F//, F///, roundino; up of the young 
spores durini^ the secretion of their cell-walls ; IX, 
mature spore, with thick and sculptured exospore 
(epispore). X 550.— After Sachs. 



42 



BOTANY. 



protoiVasm of the mother-cell is used. The former he 
calls Free-Cell Formation, ,Sii\{i 
the latter Formation of Cells 
by Division of the Mother- 
Cell, and includes also under 
the last a part of what has 
been described above under 
the head of Fission. It is 
doubtful, however, whether 
such a division is of much 
importance. 

(&) What has been called 
the Rejuvenescence of a cell 
may be mentioned here. The 
phenomena connected with it 
are as follows: The proto- 
plasm of a cell contracts, ex- 
pels a portion of the water 
contained in it, and escapes 
through a slit in its wall ; ihe 
naked mass becomes for a 
time a free-swimming zoos- 
pore, after which it secretes a 
wall of cellulose, and begins 
to grow and form new cl41s 
by fission. Cases of this kind 
occur in CEdogonium, Stigeo- 
clonium, and many other 
aquatic Thallophytes. An 
interesting fact, but proba- 
bly of no great significance, 
is that the axis of growth of 
the new. cell is perpendicular 
to that of the old one. 

While there can be no doubt 
that this process, as Sachs 

mg.Z2.-Pezizaconvexnla. .1, vertical section ^^^sists,* "must be regarded 

of The whole plant; /i, hymeninm-e.e.. the layer morphologically as the for- 

inwhi'h the spore-forming sac!« lie , <S. the tissue ,^^.- „ ^^ „ „^ , „ n 5) +i „„„ 

of the fungus envelopng the hynienium at its mation of a new cell, there 

edge ^ in a cup like manner ; at the base of tlie can be little question that it 

tissue S fine threads arise, which grow between . , , ^ j. ^ ^ ^\ ^ 

the particles of earth, i?, a small portion of the ^s Closely related to the forma- 

hymenium;.9;i, sub-hymenialLiyer of densely in- tion of zoospores described 
terwoven filaments (hyphse) ; a to /, spore-form- /^ 

ing sacs («.<fa), with thin filaments (piraphyses) above (p. 4U). ihe dilier-; 

between them. Ax-20,Bx 550.-After Sachs. ^^^^ jg ^j^^t in the formation 

of ordinary zoospores the mother-cell breaks up into more than 

* See "Text-Book," p, 9, and also "Lehrbuch," 4te Auf., where the 
author sets apart this as an entirely different mode of cell-formation. 




CELL ]^ OEM ALLOW BY DLVLSLON. 



43 



one mass before escaping ; wliile in Rejuvenescence the whole proto- 
plasm escapes without dividing. Rej uvenescence may then be regarded 




Fisr, 33.— Endosperm-cells of Phaseolus muWflorus. A, the production of new cells 
in the protoplasm of the embryo sac ; n, n, ??., nuclei ; a, a, a, masses of protoplasm 
gathered around the nuclei ; 6, young: cell, but without a wall of cellulose ; c. young 
cell with a wall ; c', (/, young cells with walls and vacuoles. B, two cells of the 
endosperm in a much later sta'ie ; ihe cells have fused their walls so as to form a 
false tissue ; in the angles between the cells are intercellular spaces filled with some 
of the protoplasm of the mother-cell (embryo sac) ; the cell a is in process of fission, 
the two nuclei n, n, are near together, as if formed by the fission of the original nu- 
cleus ; s, line indicaiing the hf)undaries of the two masses of protoplasm; the cell 
& is fully divided, and the two psirts are sep irated by the wall cL x 670.— After 
Dippelc 

as a case of internal cell-formation in which there is no division of the 
protoplasm. 



44 



BOTANY. 



56— Cell-Formation by Union. The simplest example 
of cell-formation by the union of cells is found in the Myx- 
omycetes. The swarm-spores which liave been described as 
multiplymg by division (see p. 3Gj somewhat later begin 
the opposite process of uniting. Two or 
more approach one another and gradually 
coalesce into a homogeneous protoplasmic 
mass (Fig. 34). This union appears to be 
but little more than a physical running 
together of similar drops, and possibly is a 
purely physical process. 

In Pandorina (one of the Zygophytes) 
two free-swimming ciliated cells (zoo- 
spores) come together and fuse into one 
De common body, which then surrounds itself 




Fig, 34. — Union of 
the swarm-spores of 
Chondrioderma diffor- 
me. Pars. (Didymmm 
Libertianum of 
Bary); a, two swarm- n /tti- 

spores; b, the same with a wall and becomes a new cell {rig. 

fused into one; c, three 
swarm-spores; d, the 
same a few moments 
afterward, the two up- 
per ones fused into one. 
X 390.— After Cienkow- 



149, p. 222). 

57. — In Cosmariiim, a genus of the 

Desmidiaceae, the uniting cells haye well- 
^^ developed walls, and as a consequence the 

process is somewhat different from what it is in the Myxo- 
mycetes. The cells, which in this genus are two-lobed (Fig. 
35), approach each other ; each sends out from its centre a 
protuberance which meets the other (d) ; the thin w^alls 
separating the cavities of the protuberances are absorbed, and 




Fig. 35. — Cosmariiim 3Teneg7iinu. «, b, c, different views of the mature plants, 
d, e, and/, three stages in the formation of the new cell ; g^ Ji, and z, the after-devel 
opment of the new cell, x 475.— After Oersted. 

the united protoplasmic masses form a round ball (e), which 
soon becomes enclosed in its own proper coatings (/). 

58. — The union of cells in Spirogyra is much like that of 
Cos7narium. Tif^^Q the cells are united into long filaments. 



CELL FORMATION BY UNION. 



45 



instead of being independent, as in the previous case. At 
tlie time of union the filaments approach one another and lie 
nearly parallel ; protuberances grow out from the contiguous 
cells (Fig. 36, a, b) ; their extremities meet, and the walls are 
absorbed, making a channel of communication from cell to 
cell (Fig. 36). Through this channel the protoplasm from 
one of the cells passes into the cav- 
ity of the other ; the two masses 
unite and form a round or ovoid 
cell, which soon secretes a wall of 
cellulose (Fig. 3*7, A, h, and B, c). 

Tlie particular kind of union in which 
the two cells are of equal or nearly 
equal size, and illustrated above by Cos- 
marium and Spirogyra, has received the 
name of Conjugation. It is character- 
istic of one group of the Thallophytes, 
viz., the Zygosporece. 

59. — In Vaucheria, a fresh-wa- 
ter Thallophyte, "we have an ex- 
ample of the union of cells of very 
different sizes. The larger cells 
(called oospheres) are in Literal 
protuberances of the large single 
cell which composes the whole 
plant (Fig. 38, A, and B, og). The 
protoplasm in these is of a spheri- 
cal form, and is much denser than 
in the main cell, from which it is 
separated in each case by a trans- 
verse wall (shown in F). The 
smaller cells (the speimatozoids) 
are produced by the internal cell- 
division of the protoplasm of simi- 
lar protuberances (the antheridia. A, and B, a). They are 
very small as compared with the oospheres, and are naked 
masses of protoplasm provided with two cilia, by means of 
which they are locomotive (B). Upon escaping into the 
water by the bursting of the old wall, they swim about, and 




Fig. 36.— Two filaments of Spiro- 
gyra longata about to conjugate ; 
at a and h are seen the protuber- 
ances from the contiguous < ells 
approaching each other, x 550.— 
After Sachs. 



46 



BOTANY. 



gome of them finally reach the oosphere (through a rupture 
in its wall), and unite with its protoplasm {E, F). The re- 
sult is at once seen in its greater sharpness of outline, and 
in the development of a cell-wall^, whereby the oosphere is 
transformed into an oospore. 

60. —Essentially the same kind of union takes place in the 
nearly related parasitic group, the PeronosporecB. The only 
diHerence is that here the antheridium (Fig. 39, n) comes in 
direct contact with the oosphere (o) by means of a project- 
ing tube, and through this tube the protoplasm masses of 

the two cells unite. 
The absence of mo- 
tile spermatozoids 
in this case is prob- 
ably connected with 
the fact that these 
plants live in the 
tissues of land 
plants, instead of 
being immersed in 
water. 

61.— The first cell 
of the embryo in 
mosses is the result 

the protoplasm is passing from the lower cell to the up- ^^ ^ UUlOn 01 CellS 

per ; at h the union of the two protoplasmic masses is differing* 2'reatlv in 

completed ; in B the protoplat^mic masses have se- . 06 J 

creted thick walls, thus completing the formation of sizC. 

the new cells, x 550.— After Sachs. ^^ _ 

cell lies at 




Fig. 37. -Filaments of Sjnrogyra longata ; in A, at a 



The larger 
the bot- 
tom of a flask- shaped organ, the archegonium (Fig. 40, B, 
I) ; the smaller, the spermatozoids, are developed by the in-^ 
ternal cell-division of another organ, the antheridium (Fig. 
•il. A). The spermatozoids, as in Yaucheria, are naked 
masses of protoplasm, provided with cilia, by means of 
which they swim freely through the water (Fig. 41, B). 
Upon coming in contact with the large cell in the archego- 
nium they fuse with it, and thus make a new cell. 

62. — In Phanerogams the first cell of the embryo is the re- 
sult of the union of the protoplasm contained in the pollen- 
cell with that in the embryo sac. Here again the two 



CELL FOBMATLON BY UNION: 



47 



masses come in direct contact by means of a tube (the pol> 
len tube) which touches with its lower extremity the embry- 
onic yesicle. 

{a) The foregoing classification of tlie modes of cell-formation differs 
in many respects from tliat given by Sachs in the fourth edition of his 
''*Lehrbuch." His classification as there given is as follows : 







Fig. ^%. — Vaucheria sessilis. A, origin of the lateral branches, oq (oogonium), and 
h iantheridium), from the filament ,• B. the branch a (the same as // in ^1) has it* ter- 
minal portion cut off by a partition ; in Of7 the protoplasm is becoming greatly con- 
densed ; C, the same as oq of B. but further advanced (now called an oosphere) and 
the wall burst open, permitting the escape of a drop of protoplasm sZ; D, small motile 
cells (spermatozoids) from the terminal cell of a in B ; U, the same as C, but a lit'le 
later — the spermatozoids are entering throueh the opening ; F, a, the branch a in B, 
with the terminal cell now empty, on account of the escape of the spermatozoids ; 
osp, the same as E, and og in B, after union with the spermatozoids— the protoplasm 
is surrounded by a thicK: cell-wall and it is now called an oospore. X 100.— After 
Sachs. 

A. — Formation of Reproductive Cells 

1. Rejuvenescence. 

2. Conjugation. 

3. Free Cell -Formation. 

4. Formation of Reproductive Cells by Division, which is made to 
mclude the formation of pollen, the spores of mosses and ferns, and 
the conidia, stylospores, and basidiospores of many fungi. 



48 



BOTANY. 






Fiof. 39.—Peronospora alsinearvm. A , young oogonium o, and young antheridium 
n, in contact with it ; B, the antheridium n beginning to pierce the oogonium o, whose 
protoplasm is becoming condensed ; C, the fine tube of the antheridium n has pen- 
etrated the oogonium o, and come in contact with its condensed and rounded proto- 
plasm, the oopptere. X 350.— After De Bary. 



im 




%*i^ 








Fig. 40. Fig. 41. 

Fig. 40.— Female reproductive organs of a moss, Funaria hygromelr^cn. A, apex 
o, the stem ; a, archegonia ; h, leaves : B, archegonium ; b, base ; h, neck ; m, 
mouth; C, mouth of fertilized archegonium A x ILO, -B X 550.— After Sachs, 

Fig. 41. — Male reproductive organs of tlie same moss. A, antheridium open and 
permitting the sperraatozoids a to <scape ; 2?. h. spei m-cell of another moss [Polytri- 



chum), with contained spermatozoid ; 
pointed extremity. A X 350, B X 800. 



c, spermiitozoid free, 
After IS..chs. 



with two cilia at iha 



CELL FORMATLON BY VNION. 49 

B. — FoRMATioisr OP Vegetative Cells. 

1. By the progressive formation of a division wall. 
3. By the simultaneous formation of a division wall. 
The main objection to this classification is that its principal divis- 
ions are based upon physiological distinctions alone. 

62a.— Behavior of the Nucleus in Cell-division. It has 

been shown (par. 16) that the chromatin of the nucleus is in 
the form of rods or threads wliich are imbedded in the 
hyaline achromatin. In cell-division the nucleus divides 
first, the separation of the protojplasm apparently being 
determined by the action of the nucleus. In indirect divis- 
ion of the nucleus the chromatin rods or threads divide, and 
arrange themselves in two parallel plates, one at each pole of 
the nucleus, connected by more or less well-defined achroma- 
tin fibres. The chromatin plates then become denser and 
more rounded, and eventually are the new nuclei. Direct 
nuclear division in which the nucleus constricts directly into 
two new nuclei, often takes place in the older cells of higher 
plants. 



Note on Paragraph 56. " From the researches of Schmitz on the 
Myxomycetes (Sitzber. d. nieder-rhein. Ges. in Bonn, 1879), it appears 
that the nuclei of the cells which coalesce to form the plasmodium do 
not fuse, but remain distinct : this case of coalescence of cells cannot, 
therefore, be any longer regarded as an instance of cell -formation by 
conjugation." {S. H. Vines in App. to Sachs' Text-Book of Botany. 
Second English Edition, p. 945.) 



CHAPTER V. 

PRODUCTS OF THE CELL. 

§ L Chlorophyll. 

&&. — In many plant-cells definite portions of tho proto- 
plasm have a green color, on account of the presence of a 
peculiar cliemical compound known as Cliloroj)hyll. * The 
protoplasmic bodies thus colored are called chloroj^hyll-bod- 
ies, or chlorophyll granules, while to the coloring-matter 
alone, distributed in small quantity through their substance, 
the name chlorophyll is properly applied. 

64. — The chlorophyll-bodies are of various shapes and 
sizes. In some of the lower plants nearly the whole of the 
protoplasm is colored, giving the whole cell a uniform green 
color. In others there are stellate or band-like chlorophyll- 
bodies distinct from the mass of the protoplasm of the cell ; 
the band-like bodies are straight, or more commonly spiral 
(Fig. 42). In the great majority of cases, however, the 
chlorophyll-bodies are simple rounded granules of such mi- 
nute size that many are contained in a single cell (Fig. 43). 
The chlorophyll may be dissolved out of its protoplasmic 
vehicles, leaving the latter with the appearance and chemi- 
cal properties of ordinary protoplasm. 

65. — rThe exact cliemical com])Osition of chlorophyll is not 
known. As obtained by the evaporation of its alcoholic 
solution it is a green resin-like powder, insoluble in water. 
From the partial analyses of Kromayer it is probable that it 
contains carbon, hydrogen, nitrogen, and oxygen, and there 
are good reasons for believing that iron is also one of its con- 
stituents. 

* Chlorophyll is also found to a limited extent in the animal king- 
dom. 



CHLOROPHYLL, 



51 



06. — With few exceptions chloropliyll is not found in cells 
wtich are not exposed to the action of light.* When ordi- 
nary green plants are removed for some time from the light, 
the chlorophyll disappears from the chlorophyll-bodies, and 
leayes them colorless. The same decoloration also takes 
place when a plant is deprived of 
iron as one of the constituents of 
its food. The disappearance of 
chlorophyll takes i3lace normally in 
higher plants when the cells lose 
their activity. In the case of leaf- 
cells, upon the approach of autumn 
the chlorophyll appears to be re- 
moved to other portions of the 
plant. 

{a) The cells of many Palmellacem, 
and many zoospores — e.g., of (Edogo- 
nium and VaucJieria — furnish good ex- 
amples of the coloration of nearly the 
whole body of protoplasm. 

In Zygnema the chlorophyll-bodies are 
stellate, and in Spirogyvd, spiral. 

In Vaucheria there are multitudes of 
roundish or slightly angular chlorophyll- 
bodies, which line the interior of the 
large cells. The chlorophyll in the 
leaves of many mosses may be easily 
studied, even without making sections ; 
in them the chlorophyll-bodies are round- 
ish in outline. In the higher plants thin 
cross-sections of the leaves afford the 
best means for the examination of their Y\g. 42.— Two filaments of Spl' 
chlorophyll-bodies, which are uniformly rogyra longata ; the chlorophy]! 
,^ •; T 1 XI- "^ IS lu spiral bands; in the centro 

of a simple rounded outline. of each cell la a nucleus, with 

(&) Chlorophyll is soluble in alcohol, ^^<^i,^^^^S,/*""S^ ^^ protoplasm. 
, '^ , T - , . . , T X 550.— After Sachs, 

ether, chloroform, benzine, essential and 

fatty oils, hydrochloric and sulphuric acids, and these may be used 




* The cotyledons of many Coniferae acquire a green color even in 
total darkness. The embryo of Phoradendron is green in the unopened 
seed, and in certain seeds with thick coats, which are impervious to 
light (e. g.y in some Cucurbitacece), a chlorophyll -bearing layer of cells 
surrounds the embryo. 



52 



BOTANY. 



for obtaining solutions. In tranvsmitted light the alcoholic solution is 
green, but when viewed by reflected light it appears U) be red. 

When an alcoholic solution of chlorophyll is boiled for a few minutes 
with an alcoholic solution of potash, and then neutralized with hydrochlo- 
ric acid two substances are ob- 
tained : the one as a yellow pre- 
cipitate, named PhyUoxanthine, 
and the other a blue substance 
Y^] dissolved in the supernatant 
1' - liquid ; by evaporation the lat- 
ter may be obtained as a blue 
powder, named Pliyllocyanine. 
(c) The importance of iron in 
giving a green color to plants 
is easily demonstrated by grow- 
ing young plants of Indian corn 
in solutions containing no iron. 
The first-formed leaves are 
green, but subsequently only 
colorless ones are produced ; 
alter the addition of iron in the 
form of ferric sulphate or ferric 
chloride, the colorless leaves 
become green in the course of 
a few days. 

The importance of light in 
the production of chlorophyll is 
shown in the etiolated shoots of 
the potato when grown in a 
dark cellar ; the same thing 
may be shown by germinating 
the seeds of many common 
plants in dark boxes. 

{d) The disappearance of chlo- 
rophyll is seen in the common 
Fig. 43 -Chlorophyll granules in cells of operation of blanching celery 
the leaf of a moss, Fimatia hygrometrica. A, for table use, and in the blanch- 
gianules of chlorophyll with contained starch . „ ii j j 

grains, embedded in the protoplasm of the mg of grass - blades under 
cells. B separated chlorophyll granules con- boards. U pon gradually expos- 
tainmg starch; a and b, young granules; h' , , f i ^ x -i. 

h", granules dividing ; c, d, and e, old gran- ing such colorless plants to tne 
ules ;/, granule swollen up by the action of ijo-ht rlilornnhvll is nroduced 
water; g, starch grains left after destruction ^^^^^^ cnioropnyii is proaucea. 
of chlorophyll granule by the action of water. (e) Many plants which contain 
X 550.-After Sachs. chlorophyll have their green 

color hidden by the presence of some other coloring-matter. Some- 
times this is dissolved in the water contained in the vacuoles ; this is 
the case in Coleus, in which the dissolved pigment is red. In young 
plants of Atriplex the epidermal cells aie filled with such a red solu. 
tion, hiding the green ciilorophyll-bearing cells underneath. In cer- 




STARCH. 53 

tain alffse the cbloropliyll-body itself contains other coloring-matters — 
soluble in water, however — iu addition to the chloropbyll. In F'oridea 
(red sea-weeds) this extra coloring-matter is red ; in Fucacece, brown ; 
ia Biatomacece, yellowish ; and in Oscillaiorice, blue. 

In the degradation of chlorophyll, which takes place in the walls of 
the antheridia of mosses, and in the ripening of some fruits of Phanero- 
gams, other colors than green are produced. 

(/) Plants which live parasitically upon others, as the Dodder, and 
those which are saprophytic in habit, as some fungi, are usually desti- 
tute of chlorophyll ; where the parasitism is only partial, as in Castilleia 
and Gerardia, or where the food used (stolen) by the parasite is unas.< 
i; similated, as in the Mistletoe, chlorophyll is present. In the true para- 
sifes (found mainly among the fuugi) chlorophyll is never present. 

(g) The colors of flowers are produced in various ways. In somo 
cases rounded masses, apparently protoplasmic in their nature, contain 
a red (e.g., Adonis), orange {e.g., Zinnia), or yellow (e.g., Cucurbita) color- 
ing-matter. In other cases the pigment is dissolved in the watery fluid 
of the cells ; blue and violet colors are mostly produced in this way. 
White petals are so because their external layers of cells are filleu. 
with air. An important difference beween chlorophyll and the pigments 
of flowers, is that the latter appear not to be dependent upon light for 
their production ; this may be shown by enclosing branches of morning- 
glory (IponKBO) bearing young flower-buds in a dark chamber ; when, 
the flowers expand they will be seen to have their natural colors. 



§ II. Staech. 

67. — Next to chlorophyll, one of the most important pro- 
ducts of the plant-cell is starch, an organic compound closely 
related to sugar and cellulose, and represented by the em- 
pirical formula Cj^ H^q 0^^. It occurs in the form of whitish 
or semi-transparent, rounded or slightly angular stratified 
grains, and is generally found closely packed in the interior 
of certain cells. 

68. — The form of starch grains varies greatly in different 
plants, and considerably even in the same plants ; neverthe- 
less, the general appearance of the grains in each plant is so 
characteristic that the different kinds of starch may be quite 
easily distinguished. In every case the grains have more or 
less clearly defined line3, whicli are concentrically arranged 
about a nucleus * (Figs. 44 and 45). In some cases (excep- 



* The nucleus is called the Mlum by some authors, a term which 



54 



BOTANY. 



tionally in some plants and uniformly in others) two or more 
nuclei occur in each grain ; by growth such grains become 
compound and may finally separate into as many parts as 
there are nuclei. 

69. — The inolecular structure of the starch grain has been 
determined to be similar to that of plant-cellulose. It is re- 
garded as composed of molecules, each of which is surrounded 
by a watery layer of greater or less thickness. Growth takes 
place by the intercalation of new molecules between the pre- 
viously formed ones — in other words, by intussusception, 

exactly as in the case of 
the cell-wall. During the 
formation of the grain, in 
certain portions of it the 
watery layers surrounding 
the molecules become 
thicker. When seen by 
transmitted light such 
more watery parts appear 
darker than those which 
are less watery, and an ex- 
I© amination shows that they 
^^ surround the nucleus on 
all sides in a concentric 
manner. In this way the 
starch grain comes to be 
made up of alternating 
layers of more and less 
watery substar.ce. Every watery layer is thus between two 
layers which contain less water, and so every less watery one 
lies between two more watery ones. As an increase in the 
amount of water in any portion of the starch grain de- 
creases the density of that portion, the layers just described 
may be distinguished as of greater density when having 
less water and of less density when having more water. 




Fig. 44.— Cells from the cotyledon of the pea, 
(Pisum sativum). St, starch grains with nucleus 
and concentric striiE ; a, granules of aleurone ; 
i, i, intercellular spaces. X 800.— After Sachs. 



should be abandoned, as it was originally given under the mistaken 
notion that it was the point of attachment of the starch grain while 
growing. 



STARGH. 



55 



70. — There are two kinds of starch in every starch grain. 
The great mass is made up of a more readily sokible form, 
the granulose, while the remainder, amounting to not more 
than from two to six per cent of the whole grain, is less solu- 
hle, and bears some resemblance to cellulose ; it is distin- 
guished as starch-cellulose. These two forms are intimately 
combined throughout the whole starch grain, so that upon 
the removal of the granulose by solution a perfect skel- 
eton of the grain still re- 
mains. 

71. — The first forma- 
tion of starch appears to 
take place in the cliloro- 
•phyll-bodies when they 
are exposed to the light 
(Fig. 43, B, p. 52, and 
Fig. 36, p. 45). The 
grains thus formed are 
extremely minute, and of 
different shapes and sizes 
in each chlorophyll- body; 
they do not remain and 
grow into larger grains, 
but are dissolved upon 
the withdrawal of light. 
Thus the starch formed 

during the day disappears ^% 45--Cell of endosperm of Indian corn, 
,^ -111- containing polygonal starch grains, separated by 

durmg the niffht and is thin p.'ates of protoplasm. In the figures a to fir, 
T , , ? • T , ,1 the starch grains, taken from a germinating In- 

aOUbtleSS carried to other dian corn grain, are becoming dissolved and 
Li.- ^ X 1 IX disintegrated, x 800.— After Sachs. 

portions 01 the plant. 

72.— The formation of ordinary starch grains always takes 
place in protoplasm ; in fact, they may be said to be secre- 
tions from the protoplasm, just as cellulose is said to be a 
secretion. In a cell whose cavity is filled with full-grown 
starch grains the protoplasm has almost entirely disappeared, 
3nly small portions of it remaining as thin plates or scales 
between the grains (Fig. 45). 

{a) Starch occurs in nearly all cliloropliyll-bearing plants ; it is absent 
mly in Nostocacem, OscillatoricB, and other algae whose chlorophyll- 




56 , BOTANY. 

iDodies contain an additional blue pigment. It is present in many- 
plants which are destitute of chlorophyll ; this is the case with the 
parasitic Phanerogams ; it occurs, for example, in the stem of Cuscuia, 
and in the underground portions of Orohanche and Lathrma. From 
chlorophyll-less Thallophytes (fungi), with rare exceptions, it appears to 
be absent * 

(6) The best common examples for the study of fully formed starch 
grains are the following, viz., tubers of the potato, seeds of the bean 
and pea, grains of wheat, Indian corn, rice, etc. Oat-siarch and that 
of the crocus corm exist in the form of compound grains. Of those 
named, the starch grains of the potato and the bean are the largest, 
being about .07 mm. (.003 inches) in diameter, while those of rice are 
the smallest, being about .007 mm. (.0003 inches) in diameter. 

(c) The test which is characteristic of starch is its blue coloration when 
treated with a weak solution of iodine. When the solution is strong 
the color is so intense as to appear black. A careful examination shows 
that it is only the granulose which is thus colored blue by iodine, 
but on account of its much greater quantity and its intimate mixture 
with the starch-cellulose, the blue granulose gives its color to the 
whole grain. 

{d) An indication of the correctness of the present view as to the 
structure of the starch grain and the cause of stratification may be 
obtained in two ways, as follows: 1st, by thoroughly drying the grain 
by evaporation of its water or by placing it in absolute alcohol ; all 
parts having now equal amounts of water, the striae disappear ; 2d, by 
rendering all parts of the grain capable of absorbing large quantities 
of water, as may be done by means of a weak solution of potash, as in 
this way the difference in the amount of water in different layers 
being destroyed, the striae disappear as before. 

The drying process just referred to reveals another structural pecu- 
liarity, viz., that the interior portions of the starch grain contain the 
greatest amount of water. On drying, internal fissures appear, radiating 
from a central cavity and having a narrower diameter as they pass out- 
ward, showing that the loss of water is greatest in the interior. 

{e) The separation of the granulose from the starch-cellulose may be 
accomplished in the following ways : (1) by allowing the starch grains to 
remain for a long time in a weak solution of hydrochloric or sulphuric 
acid ; the acid solution must not be strong enough to cause the grains 
to swell ; (2) by the action of saliva at a temperature of 40° to 47° C. 
(105° to 117° Fahr.). In either case the granulose is removed and the 
starch cellulose remains as a skeleton. Upon treatment with a solu- 
tion of iodine the skeleton is colored brown instead of blue. Other 

* Hofmeister, in " Lehre von der Pflanzenzelle," from which the 
preceding statements have been mainly taken, states that starch gran- 
ales occur in the oospores of Saprolegiiice. 



i 



ALEURONE AND GRT8TALL0ID8. ST 

agents, as organic acids, diastase, and pepsin, also are solvents of 
granulose. 

(/) The natural solution of starcli grains takes place in the cells of 
living: plants in a way somewhat similar to the artificial removal of 
granulose. The process is not, however, so regular and uniform; 
holes and irregular excavations are formed in the grains, sometimes 
with the removal of the granulose only, and in other cases with the 
solution of the whole substance ; sooner or later the grains break up 
into pieces, and by a continuation of the process of solution they soon 
disappear (Fig. 45, a, g). Sachs maintains that starch may thus be 
dissolved in the cotyledons of the bean and transferred to other parts 
of the plantlet, reappearing in the form of grains without undergoing 
chemical change or conversion into sugar, 

{g) Observations upon the formation and disappearance of starch 
grains in the chlorophyll-bodies are best made with Spirogyra. By 
keeping healthy filaments of this plant in darkness for some time the 
starch disappears ; upon exposure to direct sunlight the formation of 
starch begins again in about two hours ; in diffused daylight it begins 
several hours later. Other plants with thin tissues may also be used, 
as, for example, the thin leaves of mosses, etc. 

{h) The development and growth of starch grains may be studied itt 
the ripening grains of Indian corn, by making extremely thin sec- 
tions at different stages of the ripening process. They always appeal 
at first as minute solid globular masses in the protoplasm. 

§ III. Aleuroke and Crystalloids. 

73. — In the ripening of seeds and the maturation of tuber» 
the loss of water by the protoplasm gives rise to a number of 
poorly understood forms of albuminous matter. Two of the 
most noteworthy of these are AUurone, and the crystal-like 
bodies known as Crystalloids. 

74. — Aleurone occurs in the form of small rounded 
grains, sometimes occupying a great portion of the cavity of 
the cell (Fig. 44, a, p. 54). They are soluble in water,* or 
in water containing a little potash ; but are insoluble in alco- 
hol, ether, benzole, or chloroform. They frequently contain 
other bodies enclosed in their substance, as crystalloids (de- 
scribed below), globoids (composed of a double calcium and 
magnesium phosphate), and crystals of calcium oxalate. 



* The aleurone grains of Gynoglossum officinale are stated hy Sachs 
not to be soluble in water. 



58 BOTANY, 

75. — Aleurone grains appear in seeds during the last 
stages of ripening. In the turbid cell-contents, as the loss 
of water proceeds small globular masses of albuminous mat- 
ter appear, and afterward increase their size ; by the con- 
tinued loss of water they become harder and of a more defi- 
nite outline. In the germination of the seed the aleurone 
grains dissolve, and the protoplasmic contents of the cells 
assume very nearly the condition they held before the final 
changes in the seed which produced the aleurone. 

Aleurone may be studied in the seeds of tlie bean, pea, vetcli, and 
lupine, and in acorns, chestnuts, horsechestnuts, and the bran-cells of 
the oat-grain. 

The development of aleurone grains may be best studied in the 
ripening seeds of the peony. 

76. — As with the grains of aleurone, the nature of crystal- 
loids is not fully understood. They are quite certainly modifi- 
cations of protoplasm, and not true crystals, although they 
are bounded by plane surfaces, have sharp edges and angles. 
and when viewed by polarized light bear a resemblance 
to crystals. Their deportment with reagents, however, 
is similar to that of protoplasm ; thus, under treatment 
with iodine, or nitric acid and potash, and in their coagula- 
bility, they show a protoplasmic nature. They possess the 
power of imbibing water, but are not dissolved in it, and in 
a dilute solution of potash they swell greatly, at the same 
time altering their angles. They are insoluble in alcohol. 
In dilute acids or gl3'cerine one portion of their substance is 
removed, leaving a skeleton. 

77. — In form they are cubical, tetrahedral, octahedral, 
rhombohedral, and of other shapes, and there is generally 
such irregularity in their forms that it is difficult to deter- 
mine to which crystal system they belong. In most cases; 
they are colorless, but in some plants they contain a coloring- 
matter which may be removed by alcohol and acids. 

{a) Common examples for study may be obtained from the parenchy- 
ma-cells beneath the skin of the potato tuber, in which they are cubi- 
cal or tetrahedral, and imbedded in the protoplasm. 

They may be obtained from the Brazil-nut {Bertholletia excelsa) by 
placing portions of the crushed seed in a test-tube and agitating it with 
ether ; the crystalloids, which settle to the bottom, are tabular. 



(I 



GBTSTAL8. 59 

Thin sections of tbe seeds of tlie Castor Bean {Ridnus communis\ 
after the removal of other substances by soaking in water for some 
time, show tetrahedral or octoliedral crystalloids. 

(&) Aleurone and the crystalloids furnish the greater part of the al- 
buminoid portions of edible grains. The amount of albuminoids is 
presumably an indication of the amount of aleurone and crystalloids. 
The percentage of albuminoids in some air-dry grains and seeds isJ given 
below : * 

Rice 7.5 

Barley 9.5 

Indian Corn .... 10. 

Oats 12. 

Wheat 13. 

Pea 22.4 

Bean 25.5 

Vetch 27.5 

Lupine 34.5 

Aleurone and the crystalloids appear to be resting states of proto- 
plasm analogous to the resting states (sclerotia) of the plasmodia of 
Myxomycetes. 

§ IV. Crystals. 

78. — In many plants crystals of various forms occur either 
in the cavities of cells, or in the substance of the cell-walls, 
or even in intercellular spaces. They are, in the greater 
number of cases, composed of calcium oxalate, and are widely 
distributed throughout the vegetable kingdom, but appear 
to be most numerous in the higher groups, and least so in 
Bryophytes and Pteridophytes. 

79. — It is common to distinguish the acicular (needle- 
shaped) crystals from the other forms under the name of 
RapMdes ; these have but two equivalents of water of crys- 
tallization in their composition ([Ca 0]^ C^ 0^ + 2 H^ 0). 
They are found in the cavities of parenchyma-cells, and lie 
parallel together in bundles of ten to fifty or more. Upon 
shght pressure the crystals separate and escape (Fig. 46). 

The other crystals of calcium oxalate assume various 
forms, such as prisms, octahedra, etc. They have six equiv- 

* These percentages are from Wolff and Knop's tables, as given by 
Professor S. W. Johnson in his valuable " How Crops Grow." 



60 



BOTANY. 




Fig. 46.— Crystals of calcium oxalate. 
The right-hand portion of the figure 
ehows two raphis-cells of the Khabarb, 
with their contained raphides, and one 
crystal enlarged. On the left is a crys- 
tal from the beet. Much magnified. 



alents of water of crystallization ([Ca 0]2 0^ 0^+ 6 H^ 0). 
They may be simple (Fig. 47) or combined into compound 

crystals (Fig. 46) ; many of 
the former are sometimes 
found imbedded in the sub- 
stance of the cell-wall of the 
fibre-cells of certain Gymno- 
sjoerms (Fig. 
47). Simj)le 
crystals oc- 
cur also with- 
in the cell- 
cavities of 
many plants. 
The c m - 
pound forms 
are very various ; they almost always 
occur in cell-cavities, as in the beet (Fig. 
46) ; and it not infrequently happens that 
both simple and compound crystals are 
found in the same plant, even in contigu- 
ous cells, as is the case in the onion bulb. 
80. — Crystals of calcium carbonate 
(Ca CO3) occur less frequently than those 
just described. Their most striking form 
is that seen in the structures named cys- 
toliths (Fig. 48). These possess a curious 
structure ; a club-shaped or stalked out- 
growth of cellulose projects into the in- 
terior of a cell, and upon and in this mul- 
titudes of small crystals are grouped. 
Other forms of calcium carbonate crys- 
tals are to be found in plants — e.g., in the 
Myxomycetes. 

According to some observers, crystals ^^^'^'^^"^ ^^^^^^'^ '" ^^^ 




Crystals of 
late in the 
cell-wall of Welwitschia 



of calcium phosphate, calcium sulphate, niirabUis.-MtQr^^ck^ 
and silica are occasionally to be met with in plants.* 

* See an article on plant-crystals by Dr. Lancaster in the Qr. Jr. of 
Mic. Science, 1863, p. 343 ; also articles by Professor Gulliver in the 
same journal for 1864, 1866. and ISfiO. 



CRYSTALS. 



61 



{a) In studying: plant-crystals it is only necessary in most cases 
to make thin longitudinal sections, and to mount in the usual way 
in water. 

(b) The calcium carbonate crystals may be distinguished from those 
of calcium oxalate by treatment with hydrochloric acid, which dissolves 
both, the former with effervescence, the latter with none. Under 
treatment with acetic acid the calcium carbonate crystals dissolve (with 
3fEervescence, of course), while those of calcium oxalate do not dissolve, 

(c) Acieular crystals, or raphides, may be best obtained from the 
Evening Primrose, Epilobium, Fuchsia, and other Onaoraceae, also from 
the Balsam (Impatiens Bahamina), Garden Rhubarb, and the new 
growths of the Virginia Creeper, and the grape-vine. 

Raphide3 may also be obtained from some of the Monocotyledons 
with equal ease, e.g., Tradescantia, Indian turnip {Ai'iscema), Galla, 
Nardsstts, Lily-of-the-Valley, etc. 

{d) The other crystal forms are obtainable from the bark of the lo- 
cust {Rdbinia), elm, Hoya, leaves of Begonia, bulb-scales of onion, 
garlic, and leek, the root-stock of Iris, etc. 

{e) Cystoliths may be readily studied by making cross- sections of 
the leaves of Urtica., mulberry, hop, hemp, fig, Celtis, and other TJrti- 
C'leem. They are said by Sachs to occur only in this order and the 
Acanthacem.''' 




Fig. 48.— Cystolith from the epidermis of the upper surface of the leaf of Urtica 
macrophylla, from a cross section of the leaf, x 235.— After De Bary. 

(/) Plant-crystals appear to be surrounded by a thin layer of proto- 
plasm ; probably they are separated out from the cell sap only through 
the influence of protoplasm. It is further probable that they are resid- 
ual products of chemical actions in the plant, and, as they appear never 
to be made use of by the plant, we must regard them as to a certain 
extent of the nature of excretions. 



*"Lehrbuch," 4te auf., p. 69. However, cystoliths, or structures 
very much like them, may be found in the leaves of Ceanothus prostra- 
tus of Nevada and California. The student is referred to De Bary's 
" Vergleichende Anatomie der Vegetationsorgane der Phanerogamen 
und Fame," Chapters I. and III., for a full discussion of the subject of 
plant-crystals, and for a list of plants containing them. The articles 
referred to in Qr. Jour. Mic. Science will also prove helpful. 



62 BOTANY. 

§ V. The Cell Sap. 

81. — All parts of a living cell are saturated with water. It 
enters into the structure of the cell-wall ; it makes up the 
greater part of the bulk of the protoplasm, and it fills the 
vacuoles. It holds in solution (not necessarily, however, in 
equal proportions in all its parts) the food-materials absorbed 
by the plant, and the surplus soluble products of assimila- 
tion and metastasis. 

82. — Among the more important substances dissolved in 
the cell sap are Sugar and luuim. Of the former there 
are two varieties, viz., sucrose, or cane sugar (C^^ H^^ O^J, 
and glucose (or Isevulose), or fruit sugar (C^^ H^^ O^J, which 
diSer in their sweetness, as well as in other properties. 

83. — Cane sugar exists in great abundance in the cell sap 
of sugar cane, sugar maple, sugar beet, Indian corn, and in 
greater or less quantity in nearly all higher plants. Fruit 
sugar, as its name indicates, is found in many fruits, some- 
times mixed with cane sugar ; thus in grapes, cherries, 
gooseberries, and figs it is the only sugar present, while in 
apricots, peaches, pine-apples, plums, and strawberries it is 
mixed with cane sugar. 

84. — Inulin (0 ^ H^^ 0^ J is a substance related to starch 
and sugar, and found mainly in certain Comj^ositae, e.g., 
Dahlia, Heliantlins, Inula, Taraxacum, etc. It may be 
separated from, the cell sap by alcohol, glycerine, and other 
agents, and it then assumes the form of sphere-crystals. By 
boiling in dilute hydrochloric or sulphuric acid inuline is 
transformed into glucose. 

§ VI. Oils, Eesi^^s, Gums, Acids, ai^d Alkaloids. 

85. — The fixed oils, as olive, castor, linseed, and palm oil, 
are secreted in many plant-cells, particularly in the seeds. 
They occur as sejDarated drops among the other contents of 
the cells. In some instances the tissues contain from thirty- 
five to forty per cent of oil. 

86. — The essential oils, the resins, and gums are mainly 
the products of special cells in the plant. These secreting cells 



OILS, RESINS, ETC. 63 

are usually thin- walled and filled with granular protoplasm. 
The secretions are in some cases collected in drops in the 
cell-cavity, in others they are caused to pass through the 
cell-wall, while in still other instances the cell-wall ruptures, 
and permits the escape of the secreted matter. 

87. — There are three classes of essential oils, distinguished 
by their chemical composition, as follows : 

[a) The pure hydrocarbons ; these are represented by the 
formula Oj^ H^g. Oil of turpentine, obtained from the crude 
turpentine of various Conifers, is the type. Oil of lemons, 
oil of caraway, and oil of thyme are also of this class. 

(5) The oxidized essences, in addition to carbon and hy- 
drogen, have oxygen in their composition. Of this nature 
are camphor (0^^ H^g 0), essence of cinnamon, essence of 
wintergreen, etc. 

(c) The sulphuretted essences contain sulphur. To this 
class belong the essential oils in mustard, horseradish, and 
other Cruciferse, in onions, garlic, asafoetida, etc. That in 
garlic, which may be taken as the type, is a sulphide, 
([C3HJ2J S), while that of the mustard is a sulpho-cyanide 
(C,H„ CNS). 

88. — Eesins are much like the essential oils in composition, 
and are generally associated with and dissolved in them. 
"When separated from the essential oils by heat, the resins are 
transparent or translucent brittle solids, insokible in water, 
but soluble in alcohol. Common rosin, which is the resi- 
due left when the crude turpentine derived from several spe- 
cies of pines is distilled with water, may be taken as the type. 
It is an oxidized hydro-carbon, i.e., it contains carbon, hy- 
drogen, and oxygen. 

89. — Gums. Under this name many different kinds of 
products are commonly included. Some of them are with- 
out doubt related to the resins, while others are allied to 
starch and sugar. Of the latter kind gum-arabic (C,^ H^^ 0^) 
is the type, and allied to it are cerasin (from the cherry), 
bassorin (gum tragacanth), and vegetable mucilage, which 
is abundant in mallow roots. 

90. — Pectin, or vegetable jelly (Cj^H^gOgJ, is related to 
the foregoing ; it forms, when moist, a transparent jelly, and 



64 BOTANY. 

dries into a translucent mass. It gives the firmness and con- 
sistence to apple, currant, and other fruit jelHes. Unripe 
fruits contain a substance insoluble in water, alcohol, and 
ether, which, during the process of ripening, or under the 
action of heat, acids, and ferments, is converted into pectin. 

91. — In addition to oxalic acid (C^ H^ OJ, which is found 
generally combined with calcium, there are other vegetable 
acids, some of which are even more common ; they occur 
either free, or united with organic or inorganic bases. 

{a) Malic Acid (C^ Hg J is abundant in many sour fruits 
— e.g., apples, cherries, strawberries, currants, etc.; it is 
likewise abundant in rhubarb, where it accompanies oxalic 
and phosphoric acids. 

{h) Tartaric Acid (C^ H^ Og) occurs in the grape, tama- 
rind, berries of the mountain ash (unripe), and other plants. 

(c) Citric Acid (C^ Hg OJ is found in abundance in the 
lime, lemon, and other fruits of the Aurantiaceae. It also 
occurs in other sour fruits associated with malic acid, as in 
gooseberries, raspberries, strawberries, cherries, etc. 

{d) Tannic Acid (C^^ 11^2 0^^) occurs in the bark and 
leaves of oak, elm, willow, and many other trees, in the 
wood and bark of sumach and whortleberry, and the roots of 
some Eosaceae and Polygonaceae, and gives to them their as- 
tringency. 

Nearly related to tannic acid is quinic acid, which occurs 
in the bark of Cinchona (Peruvian Bark) in combination 
with organic bases, of which quinia is the most important. 

There are many other substances which occur in plants as 
the products of cells — e.g., the vegetable alkaloids, many 
coloring-matters, etc. As, however, this whole matter be- 
longs rather to Organic Chemistry, it will not be carried 
further in this place. 



CHAPTER VL 



TISSUES. 
§ I. The Vaeious Aggregations of Cells. 

In the organisms wliich compose the vegetable kingdom 
cells are found principally under the following conditions of 
aggregation :■ ' 

92._(1.) Single Cells. A large number of the lower 
plants, during all or a considerable part of their existence, 
are composed of single cells. They may be round, as in 
Saccharomyces and Protococcus, or elongated or even filiform, 
as in certain Bacteria. It is only in the lowest groups that 






Fig. 49.—Pediastrum granulatnm. A, the young cells in their motile state, en- 
cloBed in the membrane of the mother-cell. B, the young cells beginning to arrange 
themBelves in a cell-family. C, the cell-family fully developed.— After Braun. 

adult plants are composed of single cells, but it is an 
embryonic condition of all others. 

93. — (2.) Families, or Spurious Tissues. There are 
some oases in which cells which are at first distinct after- 
wards become united more or less closely into a common 
mass, which may be denominated a Cell-Family, or Spurious 
Tissue. 

{a) Pediastrum and Hydrodictyon furnish the best examples of true 



66 



BOTANY. 



cell-families ; in botli cases separate motile cells (zoospores) in a mother- 
cell arranore themselves in a definite manner, and gradually unite into 
a family resembling the parent plant (Fig. 49). By the breaking up of 
the wall of the mother-cell the new family is set free. 

(b) In some fungi the cells composing the vegetative threads (hy- 
phae) unite loosely with one another into a mass. In some cases the 
union is so slight that the hyphse may be separated with the greatest 
ease, while in others it approaches the density and firmness of true 
tissues (Fig. 50). While the term Cell-Family may be applied to such 
aggregations of cells, the common one of Spurious Tissue is to be pre- 
ft^rred * 

(c) In the embryo sac of Phanerogams the cells are at first sepaiate ; 




Fig. 50. — Rhizomorpha sitbcorticalis (the compact mycelium of a fungns). The 
left hand figure shows a longitudinal section of the growing end of a young shoot. 
The right hand figure shows a cros8-«er-tiou of the same ; a, the central pith-like por- 
iion ; 6, the cortical portion of smaller cells ; A, the hairy coat, which is often 
wanting. X 100.— After De Bary. 

these afterward unite into a mass which cannot be distinguished by 
any structural character from a true tissue. (See Fig. 33, p. 48.) As, 
however, the component cells were originally separate, the resultinof 
mass must be classed with the spurious tissues. 

94 — (3.) Fusions. It frequently happens that the separat- 
ing walls of contiguous cells are absorbed and their cell- 
cayities merged into one. In this way long tubes (vessels) 



* This i« the " Tela contexta ' ' of some authors. 



THE AQORmOATIONS OF CELLS. 



67 



are formed. These may extend in any direction, but they 
generally run parallel to the axis of that i)art of the plant in 
which they are found. Other cell-fusions give rise to irreg- 
ular branching tubes, or they may even form an extended 
network {e.g., in the laticiferous tissue of Cichoriaceae, Fig. 
65, p. 75). 

95^ — (4.) Tissues. A tissue may be defined as an aggre- 
gation of similar cells (or cell-derivatives) connately united. 
There are three conditions of aggregation : 

[a) Cell-rows. In these the cells are united by their ends 
into a row or filament. Such simple tissues result from cell- 
fission in one direction only. In some cases, as in Oscilla- 

A 




Fig._51. — Succulent parenchyma from the stem of Indian corn ; transverse section, 
gw^ simple plate of cellulose, forming the partition-wall between two cells ; z, s, 
intercellular spaces caused, by splitting of the walls during rapid growth, x 550. 
—After Sachs. 

toriaf the cells are short and broad, while in others — e.g., 
Spirogyra, Zygnema, and the hyphae of many fungi — they 
are cylindrical or greatly elongated. Numerous cases occur 
in the higher plants, the most familiar being jointed hairs. 

{h) Cell-surfaces are composed of a single layer of cells. 
They result from cell-fission in two directions. Examples 
may be found in many Ulvacese, and in the leaves of some 
Bryophytes. 

(c) Masses. Where the cell-fission has been in three di- 
rections the result is a mass of greater or less solidity. Fre- 
quently, through cell-fusions, the elements which compose 
such masses are cell-derivatives, instead of cells ; these may 
be regarded as tissues of a higher order. 



68 



BOTANY 



96. — The Cell-wall in Tissues. In tissues the walls which 
separate contiguous cells are at first simple and homogeneous. 
The plate of cellulose which first forms between two sister 
masses of protoplasm in cell-fission is a single one, the com- 
mon property, as it is the common secretion, of the proto- 
plasm masses. As the wall becomes older and thicker, and 
stratification takes place, it shows a line of separation into 
two halves ; this may become so well marked as actually to 
result in the splitting of the wall, as is the case in succulent 
tissues when, on account of a particular kind of tension, 
intercellular spaces are formed in the angles between the 
cells (Fig. 51). 

97. — By a still further differentia- 
tion, after a considerable thickness of 
the'^ wall has been attained, there 
mar| arise a common middle lamella, 
which, appears at first sight to lie 
between the original cell-walls (Fig. 
52). This middle lamella, which is 
simply the result of a particular 
stratification, was long mistaken for 
an intercellular substance, and two 

Fiff. 52. — Cells of the woody ,, . iii /•- ±_ r\ 

part of the young stem of tlicories wcrc held as to its nature. On 
section'^'t'J^vity o^cdlTm! the onc hand, it was supposed to be 
^o?t?iniTw\\i''^x1oS.- a^ <^"i§inal common matrix, in which 
After Sachs. ^I^q qqW^ tliemselvcs wcrc imbedded ; 

and on the other, it was held to be of the nature of an ex- 
cretion from the surrounding cells into the intercellular 
spaces. The first of these theories was possible only so long 
as the knowledge of the origin and development of cells was 
exceedingly defective. The second theory is rendered ex- 
tremely improbable by our present knowledge of the mode 
of growth of the cell-wall by intussusception. 

Until recently another view has been largely held, name- 
ly, that the middle lamella was to be regarded as the original 
common wall of the cells, and that the remaining portions 
were after-deposits upon it. This view gave rise to the terms 
Primary Cell-wall and Secondary Cell-wall, which are still 
used to some extent. As this explanation of the structure 
rests upon the all-bat-abandoned theory of the thickening 




THE PRINCIPAL TIS8UE8. 



m 



of the cell-wall by tlie addition of successiye internal layers, 
and is directly contradicted by the well-established doctrine 
of growth by intussusception, it must be regarded as erroneous. 
In some cases, as in the wood of Pinus sylvestris, the dif- 
ferentiation is so great that three lamellae are formed : (1) 
the common middle one, (2) an inner, and (3) an inter- 
mediate one. (Fig. 16, p. 26.) 



§ II. The Peikcipal Tissues. 

98. — There are yery many kinds of tissues, distinguished 
from each other by characters of 
greater or less importance. 
They all, howeyer, pass into 
one another by almost insensi- 
ble gradations ; hence by not- 
ing all the slight differences we 
may make a long list of tis- 
sues ; while by noting the simi- 
larities and gradations, all, or 
nearly all, the forms may be re- 
duced to one. The principal 
yarieties only will be noticed in 
this place ; each one, as here 
described, includes many yarie- 
ties. 

99. — Parenchyma. This is 
the most abundant tissue in the 
yegetable kingdom ; it is at once 
the most important and the 
most yariable. As here restrict- 
ed it is composed of cells whose walls are thin, colorless, or 
nearly so, and transparent ; in outline they may be rounded, 
cubical, polyhedral, prismatic, cylindrical, tabular, stellate, 
and of many other forms.* When the cells are bounded by 
plane surfaces, generally, but not always, the end planes lie 
at right angles to the longer axis of the cells. 




Fig. 53.— Merietem-cells of stem of 
Vicia faba in process of division. X 
300.— After Prantl. 



* Unfortunately, tlie terms parenchyma and parenchymatous liave 
often been restricted in meaning to tissues composed of cells whose 
three dimensions are equal. 



70 



BOTANY. 




This tissue makes up the whole of the substance of many 
of the lower plants. In the higher plants the essential por- 
tions of the assimilative (green), vegetative (growing), and 
reproductive parts are composed of parenchyma. 

Instructive examples of parenchyma may be obtained in the growing 
ends of shoots (Fig. 53) and in the pith of Dicotyledons, in tlie ends of 
young roots— 6. g., of Indian corn— in the green pulp of leaves, in the 
pulp of fleshy fruits, and in the substance of young embryos. 

100.— CoUenchyma. The 



cells of this tissue are elon- 
gated, usually prismatic, and 
their transverse walls are most 
frequently horizontal, rarely 
inclined. With few excep- 
tions* there are no intercellu- 
lar spaces. The walls are 
greatly thickened along their 
longitudinal angles, while the 
remaining parts are thin (Fig. 
21, p. 30). The cells con- 
tain chlorophyll, and retain 
the power of fission, f Wet 
specimens show by transmit- 
ted light a characteristic blu- 
ish white lustre (Figs. 54 and 
55). 

CoUenchyma is found be- 
neath the epidermis of Dico- 
tyledons (and some ferns), 




tjDr 

Fig. 54.— Transverse section of collen- 
chyma (eo) of the stem of Echinocystis 
lobata, wet with water, and the angles 
greatly swollen, ep, epidermis, with 
thickened outer wall. X 700. From a ..^ » . n 

drawing by J. c. Arthnr. usually as a mass 01 Conside- 

rable thickness, and is doubtless developed from parenchyma 
for the purpose of giving support and strength to the epi- 
dermis. 




* In the collenchyma of SllpJiium perfoliatum there are many lon- 
gitudinal intercellular spaces of various sizes ; in Ipomosa purpurea 
there are minute ones. 

f De Baiy states that collenchyma-cells are capable of fission. 
' ' Vergleichende Anatomic der Vegetationsorgane der Phanerogamen 
und Fame," p. 126. 



II 



TliE PEmCIPAL TISSUES, 



n 



(a) Collencliyma may be studied in tlie stems, petioles, and leaf-riba 
of herbaceous Dicotyledons — e.g., in species of Silphium, Rheum, 
Mumex, Ohenopodium — in many LaMatm, Solanacece, BegoniaeecB, Cu- 
curbitacece, and many others; also in the petioles of the water-lily 
and young stems of the elder, 

(&) Upon soaking in water, or upon treatment with nitric or sulphu- 
ric acid, the thickened angles become greatly swollen. 




Fig, 55,— Longitudinal radial section of stem of Echinocystis lobata. ep, epidermis; 
CO, collenchyma ; pa, parenchyma;/, a single wood fibre, marked with "crossed 
{i.e., twisted) pits ; sp, intercellular spaces, x 500. From a drawing by J. C. Arthur. 



(c) Upon treatment with Schultz's Solution the thickened angles are 
colored light blue. 

{d) Upon slight warming in a solution of potash, and then treating 
"With a solution of iodine in potassium iodide, the thickened angles be- 
come colored dark blue. 

101.— Solerenchyma. In many plants the hard parts are 
imposed of cells whose walls are thickened, often to a very 



n 



BOTANY. 



considerable extent. The cells are usually short, but in some 
cases they are greatly elongated ; they are sometimes regular 
in outline, but more frequently they are extremely irregular. 
They do not contain chlorophyll, but in some cases at least 
(e.g., in the sclerenchyma-cells in the 2^ith of apple-twigs) 
they contain starch. 

Sclerenchyma occurs in Bryophytes, Pteridophytes, and 
Phanerogams. 

(a) Good specimens of sclerencliyma may be obtained for study by 
making longitudinal sections of tbe rliizome of Pteris aquilina, in 




56^. 



Fig. 56.— Twosclerencliyma-cells from the hypoderma of the rhizome of Pteris 
aquuina^ isolated by Scliulze's maceration. A, a very thick-walled cell, with branch- 
ing pits ; B, a cell with walls less thickened— the wall of the oppoeite side of the 
cell is seen to be filled with numerous pits, x 500.— After Sachs. 

Fig. 57.— Margin of leaf of Pimis pinaster, transverse section, c, cuticularized layer 
of outer wall of epidermis ; i, inner non-cuticularized layer ; c', thickened outer 
wall of marginal cell ; g, i', hypoderma of elongated s lereuchyma ; p, chlorophyll- 
bearing parenchyma ; pr, contracted protoplasmic contents, x 800.— After Sachs. 

which it occurs as a thick hypodermal mass ; by boiling in potassium 
chlorate and nitric acid (Scliulze's maceration) the cells may be com- 
pletely isolated (Fig. 56, A and B). 

(&) The cells of the medullary rays of woody Dicotyledons — e.g.^ 
Acer, Pirus, Ostrya, Liriodendron, etc. — are generally thick-walled 
when old, and in this state must be classed as sclerenchyma. 

(c) The hypoderma of the leaves of pines consists of elongated scle- 
renchyma-cells, which at first sight might easily be mistaken for bast 
fibres (Fig. 57, g, i). The hypoderma of many other plants appears to 
be of a similar nature. 



Packi 



THE PRINCIPAL TISSUES. 



73 



(d) Theliard tissues of nuts and of stone fruits furnisli excellent ex- 
amples of short and very thick- walled sclerenchy ma-cells. In the 
hickory nut {Cari/a alba) the cells (Figs. 58 and 59) are not more than 




Fig. 58. 



Fig. 59. 



Fig, 58. — Sclerenchyma-cells of the shell (endocarp) of the hickory-nut ( Car ?/« 
■alia), taken parallel to the surface of the nut. x 400. 

Fig. 59.— Sclerenchyma-cells of the shell (endocarp) of the hickory-nut (Carya 
<llba), taken at right-angles to the surface of the nut. X 400. 



two or three times as long as broad, and the thickening is so great as 
almost entirely to obliterate their cavities; the thickened walls are 
c ^ a 




Fig. 60. 



Fm. 61. 



Fig. 60.— Sclerenchyma-cells of the seed-coat of EcMnocystis lobata, from a section 
at right angles to the surface of the seed ; a, a cell cut directly through its centre, 
showmg the whole of the cavity— the three dark ppots are probably oil ; &, a cell 
cut through at one side of the middle ; c, a cell whose cavity was not cut into in 
making the section, x 250. From a drawing by J. C. Arthur. 

Fig. 61.— Sclereiichyma-ceils of the seed-coat of Echinncystia lobata, from a section 
parallel to the surface of the seed, x 2"i0. From a drawing by J. C. Arthur. 

pierced by many deep pits. The cells are arranged with their longer 
axes perpendicular to the surface of the nut, and are very closely 
packed together. 



n 



BOTANY, 



[e) The seed-coat of EcMnocystis lohata is composed almost entirely 
of sclerenchyma (Fig. 00). Tlie cell-walls are greatly thickened, and 
tlie cells are very closely packed together, so much so that all are 
sharply prismatic (Fig. Gl). 

102.— Fibrous Tissue. This is composed of elongated^, 
thick-walled, and generally fnsiform elements, the fibres 
(Figs. 62 and 63), whose walls are usually marked with 
simple or sometimes bordered pits. These elements in cross- 
section are rarely square or round, but most generally three 
to many-sided. They are found in, or in connection with, 
the fibro-vascular bundles of Pteridophytes and Phanero- 
gams, and give strength and hardness to their stems and leaves. 





Fig. 62. Fig. 63. 

Fig. 62.— Wood fibres of Acer dasycarpum. isolated by Scbulze's maceration. a» 
four fibres, X 95 ; 6, a portion of a fibre, x 230, showiBg the diagonally placed elon- 
gated pits ; c, the ends of eleven united fibres, x 95. 

Fig. 63.— Bast fibres of Acer dasycarpvm, it-olated by Schnlze's maceration, a, a 
fibre. X 95 ; 6, a portion of a fibre, X 230, showing the much-ttiickened wall. 

Two varieties of fibrous tissue may be distinguished, viz., 
(1) Bast (Fig. 63), and (2) Wood (Fig. 62). The fibres of 
the former are usually thicker walled, more flexible, and of 
greater length than those of the latter. In both forms the 
fibres are sometimes observed to be partitioned. * 

* These partitions liave generally been considered as formed subse* 
quently to the fibres; but it may well be questioned whether, in some 



i 



THE PRINCIPAL TISSUES, T5 

To examine fibrous tissue it is only necessary to make tliin longitudi- 
nal slices of the stems of woody plants — e.g., Acer, Pirus, etc. — and to 
heat for a minute or less in nitric acid and potassium chlorate. The 




ri£?. 64. — Laticiferous tubes from Er/phorbia. A. moderately magnified; B. more 
highly magnified, and showing the bone-shaped or dumb-bell-shaped starch grains.— 
After S:ichs. 

Fig. 65.— Laticiferous vessels of Scorzonera mspnmea. ^, a transverse section ot 
the phloem of the root ; B. the same more highly magnified. — After Sachs. 

fibres may now be separated under a dissectinir microscope, or the 

cases at least, the fibres are not cell-derivatives, and the partitions the 
persistent walls of the original component cells. 



76 



BOTANY. 



specimens may "be transferred to a glass slide and dissected by tapping 
gently upon the centre of the cover-glass. 

103. — Laticiferous Tissue. In many orders of Phanero- 
gams tissues are found wliose component elements contain a 
milky or colored fluid — the latex. To these, although vary- 
ing greatly in structure and position, the general name of 



Laticiferous tissues has been given. 

city 



For the sake of simpli- 
two general forms may 
be distinguished : (1) that 
comjposed of simple or 'brandl- 
ing elements (Fig. 64), which 
are scattered through the 
other tissues. As ' found in 
Euphoi'hiacece, where they oc- 
cur in parenchyma, they are 
somewhat simply branched, 
and have very thick walls 
(Fig. 64, B) ; in other orders 
they are thin walled and are 
sometimes inclined to anasto- 
mose. From their position it 
is quite certain that the ele- 
ments of this form of laticif- 
erous tissue frequently replace 
bast fibres. In such cases 
!?,•„ aa T +• -f ^^ f^v. ■ ^^GV are said to be metamor- 

Fig. 66 —Laticiferous cells of the onion, -^ 

from a longitudinal seciion of a scale of phoscd bast fibres ;* in othcr 
tne bulb. €, epidermife with cuticle c ; jK ^ ,-, 

parenchyma; sg, coagulated contents of caseS, llOWeVCr, tliev appear 
laticiferouscells, contracted so as to show . i i j> ±-i • ^ i , 

the porous walls ; g, ^, transverse wall.— UOt tO DC 01 thlS nature, but 

After Sachs. ^^ ^^.^^^ from the parenchyma 

by the absorjotion of the horizontal partition- walls, f 

* There is an objection to the word metamorphosed in this connec- 
tion, as it does not exactly express the relation between the laticiferous 
elements and the bast fibres. It mast not be understood that the 
former are made by a transformation of the formed bast fibres ; the 
relation is rather that they develop from what under other circum- 
stances would have developed into bast fibres. We may express the 
relation by saying that laticiferous elements and bast fibres are closely 
related sister elements. 

f '* According to Hanstein.it is probable that in some Aroideae vessels 




THE PRINCIPAL TISSUES. 77 

(2. ) The other form is that composed of reticidately anas- 
tomosmg vessels. Here the tissue is the result of the fusion 
of great numbers of short cells. The walls are thin and 
often irregular in outline. In Ciclioriacece this form of 
laticiferous tissue is very perfectly developed as a consti- 
tuent part of the phloem portion of the fibro-vascular 
bundles (Fig. 65, A and B), 

{a) Laticiferous tissue has not yet been shown to contain either pro- 
toplasm or nucleus.* The latex is an emulsion of several substances, 
some of which, as caoutchouc, (India-rubber), gutta-percha, and opium, 
are of great economic importance. In some cases, as in Euphorhia, 
grains of starch are contained in the latex (Fig. 64, B). 

{b) The chemical composition of latex is shown by the following 
analyses, as given by De Bary : f 

Latex of Hevea Ouianensis, as determined by Faraday : 

Water with an organic acid 56.3 per cent. 

Caoutchouc 31.7 " " 

Albumen 1.9 " 

Bitter nitrogenous matter, with wax 7.1 " " 

Residue soluble in Ha O, but insoluble in alcohol. 2.9 " " 

99.9 

ijatex of Oalactodendron utile, as determined by Heintz : 

Water. 57.3 per cent. 

Albumen 0.4 " 

Wax (C35 Hee O3) 5.8 " 

Resin (C35 Hss O2) 31.4 " 

Gum and sugar 4.7 " 

Ash 0.4 " 

100. 

Latex of Euphorbia eyparissias, determined by Weiss and Wiesner ; 

Water 72.1 per cent. 

Resin 15.7 " 

Gum 3 6 " 

Sugar and extractive substances 4.1 " 

Albumen 0.1 " 

Ash 0.9 " 



of the xylem assume the form and function of laticiferous vessels.* 
Sachs' " Text-Book of Botany," English edition, p. 110. 

* The latex of some Cichoriaceae coagulates much like protoplasm 
possibly further investigation will show it to be present. 

f "Anatomic der Vegetationsorgane," etc., p. 194. 



78 



BOTANY. 



(c) Examples of the simpler forms of laticiferous tissue may be ob- 
tained for study from Euphorbiacem, Urticacece, AsdejnadacecB, Apocy- 
nacecB. Forms less simple occur in AracecB, and in the maple ; in the 
last-mentioned they appear to replace the sieve-vessels. Related to 
these again are the peculiar milk-vessels of the onion (Fig. 06), which 
consist of elongated cells separated by thin or perforated septa. 







Fig. 67. — Longitudinal 
section through the sieve 
tissue of Cucurbita Pepo. 
Q, q, section of transverse 
sieve - plates ; si, lateral 
sieve-plate ; x, thin places 
in wall ; I, the same seen in 
section ; ^;5, protoplasmic 
contents contracted by the 
alcohol in which the speci- 
mens were soaked ; sp, pro- 
toplasm lifted off from the 
sieve-piale by contraction ; 
si, protoplasm still in con- 
tact with the sieve-plate ; ?, 
parenchyma between sieve 
tubes, X 550. —After 
Sachs. 



{d) The more complex or reticulated forms of laticiferous tissue 
occur in Cichoriacece, Campanula cece, Loheliacece, ConvolvulacecE, Pa- 
yaveracece. 

{e) By heating thin sections of any of the foregoing plants in a di- 
lute solution of potash the laticiferous tissues may be readily isolated 
for study. 

) The walls of the laticiferous elements are always rich in water, 
and are composed of cellulose, as may be shown by the blue coloration 
which follows treatment with Schultz's Solution. 



THE PRINCIPAL TISSUES. 



79 



104. — Sieve Tissue, As found in tlie Angiosperms this 
tissue is made up of sieve ducts and the so-called latticed 
cells. The former (the sieve ducts) consist of soft, not 
lignified, colorless 
tubes of rather wide 
diameter, having at 
long intervals horizon- 
tal or obliquely placed 
perforated septa. The 
lateral walls are also 
perforated in restrict- 
ed areas, called sieve 
discs, and through 
these perforations and 
those in the horizontal 
walls the protoplasmic 
contents of the con- 
tiguous cells freely 
unite (Figs. 67 and 
68). In many plants 
the sieve discs close up 
in winter by a thick- 
ening of their sub- 
stance (Fig. 69). 

The tissue composed 
of these ducts is gene- 
rally loose, and more 
or less intermingled 
with parenchyma; in 
some cases even single 
ducts run longitudin- 
ally through the sub- 
stance of other tissues. 
In the form described 
above it is found only 
as one of the compo- 
nents of the i)hloem x 145 
portion of the fibro-vascular bundle. 
105. — The so-called latticed cells 




Fig. 68.— Longitudinal tangential section of the 
young bark of the grape (Fi^is vinifera), taken in 
the beginning of July, s, s, sieve tubes, with sec- 
tions of the transverse plates— in the left-hand sieve 
tube, at the top of the figure a lateral plate is 
shown ; »i, m, medullary rays, with crystals in 
some of the cells— between the sieve tubes them- 
selves, and between them and the medullary rays, 
ae masses of parenchyma (phloem parenchyma). 
After De Bary. 



ar3 probably to be 



80 



BOTANY. 



% 



regarded as undeveloped sieve ducts, and hence the tissue 
they form may be included under sieve tissue. Latticed 
cells are thin-walled and elongated ; they differ from true sieve 
ducts principally in being of less diameter, and in having 
the markings but not the perforations 
of sieve discs. Both of these differences 
are such as might be looked for in un- 
developed sieve tissue. 

106. — In the corres- 
ponding parts of the vas- 
cular bundles of Gymno- 
sperms and Pterido- 
phytes a sieve tissue is 
pU found which differs 

=^( U'J L somewhat from that in 

Angiosperms. In Gym- 
nosperms the sieve discs, 
which are of irregular 
outline, occur abundant- 
ly upon the oblique ends 
and radial faces of the 
Fig. 69. — Longitudinal broad tubes (Fig. 70). 

tangential section of the y -p). • i i j. xi 

young bark of the grape, In Pteridoj)hytes the 

{Vitis mnifera), taken in i,,-u„„ hu^ra -trnwiTio- 

winter; the sieve plate is tUDCS UaVC ^aiyiUg 

closed up by the thickening -p^,™,„ . ,• Wai/i^pfoim 

of its substance. X 400.— ■^^^^^^ y i". J^quisezum 
After DeBary. ^ud OpUogloSSUm they 

are prismatic, with numerous horizontal but 

not vertical sieve discs ; in Pteris and many 

other ferns they have pointed extremities, 

and are greatly elongated, bearing the sieve 

discs upon their sides (Fig. 71). In the 

larger Lycopodiacece the sieve tubes are pris- ^glgan^m.^^tlTeu 

matic and of great length ; in the smaller oid°sfem^Ti^e deve 

species there are tissue elements destitute of plates are'piacediat- 

^ erally and are com- 

eieve discs, but which are otherwise, includ- posed of many little 

. . ,1 , XT Ti .1 punctured areas 

mg position m the stem, exactly like the grouped together ir- 

• "^ x 4? XT, 1 • regularly, x 375.— 

Sieve ducts of the larger species. After De Bary. 

{a) Good specimens of sieve tissue may be obtained for study by 
making longitudinal sections of tlie stems of Cucurhita, CucumiSt 




Fig. 70. — Eadial 
view of the end of a 



THE PRINCIPAL TISSUES. 



81 



EcMnocystis, Ecbalium, Vitis, Bignonia, and Calamus Rotang ; also 
Abies pectinata, Larix, Juniperus, Sequoia, and Ginkgo ; also Pteris, 
Osmu7ida, Equisetum, and Lycopodium. 

ih) By making repeated horizontal sections the horizontal sieve discs 
may be found and studied, 

(c) Alcoholic specimens afford much more satisfactory results than 
fresh ones ; especially is this the case with the more succulent plants. 




Fig. 71. — Sieve tissue of Pteris aquilina. A, end of a sieve tube isolated by macer- 
ation J B, portions of two tubes seen iu vertical section ; in s' the sieve plates are 
seen m front view ; at c, c, they are seen in section ; the tube s^ has sieve plates 
on its right and left walls, but none on its further wall, which is in contact with pa- 
renchyma-cells ; two of the latter are seen to have nuclei in them, x 375,— After De 
Bary. 



107. — Tracheary Tissue. Under this head are to be 
grouped those vessels which, while differing considerably in 
the details, agree in haying thickened walls, which are perfo- 
rated at the places where similar vessels touch each other. The 



82 



BOTANY. 



thickening, and as a consequence the perforations, are of 
Yiirious kinds, but generally there is a tendency in the former 
to the production of spiral bands ; this is more or less evident 
even when the bands form a network. The transverse parti- 
tions, which may be horizontal or oblique, are in some cases 
perforated with small openings, in others they are almost or 
entirely absorbed. The diameter of the vessels is usually 
considerably greater than that of the surrounding cells and 
elements of other tissues, and this alone in many cases may 
serve to distinguish them. When young they of course con- 
tain protoplasm, but as they become older this disappears, 
and they then contain air. 

108. — Tracheary tissue is found only in Pteridophytes 




Fig. 72.— Longitudinal section of a portion of the stem of Impatiens Balsamina. v, a 
ringed vessel ; v', a vessel with rings and short spirals ; v", a vessel with two spirals ; 
v'^^ and v^^^\ vessels with branching spirals ; ■w'''"''', a vessel with irregular thicken- 
ings, forming the reticulated vessel.— After Duchartre. 



and Phanerogams. The principal varieties of vessels found 
in tracheary tissues are the following : 

(1.) Spiral Vessels, which are usually long, with fusiform 
extremities ; their walls are thickened in a spiral manner 
with one or more simple or branched bands or fibres (Fig. 
72, v", v'", v""). This form may be regarded as the typical 
form of the vessels of tracheary tissue. In most cases the 
direction of the spiral is from right to left.* It is frequent- 
ly in one direction in the earlier formed spirals and the op- 

* Right to left, in speaking of these spirals, as also in describing the 
twining of certain climbing plants, is passing up and around in the di- 
rection of the hands of a watch. Left to right is of course up and 
n round opposite to the hands of a watch. 



i 



TEE PRINCIPAL TISSUES. 



83 



posite in those formed later ; while in interrnpted spirals 
both directions occur in the same yessel. Rinyed and reticu- 
lated yessels are opposite modifications of the spiral form ; 
A JB 




Pig. 73.— Scalariform vessels of the rhizoma of Pteris aquilina. A, longitudinal sec- 
tion of an end (about one third of the whole) of a short vessel ; /, the fusiform ex- 
tremity, with long pits placed transversely; B, a small portion 6i A, taken from tc, 
and much more highly magnified ; C, a longitudinal section of a portion of the side 
wall between two vessels ; D, a similar section through the inclined end wall {A,f) ; 
in the upper part of D, at/ the wall between the thickening ridges is broken through. 
A, X 142 ; the others x 375.— After De Bary. 

the first are due to an under-development of the thickening 
forces in the young vessels, resulting in the production here 
and there of isolated rings (Fig. 72, v) •, reticulated vessels 
are due, on the contrary, to an ov^r-development, which 



84 



BOTANY. 



gives rise to a complex branching and anastomosing of the 
spirals (Fig. 72, v'""). 

(2.) Scalariform vessels. These are prismatic vessels whose 
walls are thickened in such a way as to form transverse 
ridges, as described in paragraph 32, page 28. They are wide 
in transverse diameter and their extremities are fusiform or 
truncate (Fig. 73). 

(3.) Pitted Vessels. The walls of 
these vessels are thickened in such a 
way as to give rise to pits and dots, 
as described in paragraph 31, page 
26. The vessels are usually of wide 
diameter ; in some forms they are 
crossed at frequent intervals by per- 




FiG. 74. 



Fig. 75. 



Fig. 74.— Pitted vessels of Aristolochia sipho, from a longitudinal section of the 
stem ; tlie vessel on ihe right is seen in section, that on the left from without ; aji. 
rings, which are remnants of the original transverse partitions ; b, b, sections of tht; 
walls ; between the vessels are parenchyma-cells, highly magnified. — After Duchartre. 

Fig. 7.5 — Tracheides of Cyfuus labinn/mi. fvom a longitudinal tangential section 
of the stem ; m, m, a cross-section of a medullary ray ; in ihree of the cells the pitted 
partitions are seen ; the meduUnry ray is surrounded by tracheides, which are spi- 
rally marked and sparingly pitted ; at g, two tracheides have fused by the breaking 
of the wall ; s, s, slightly modified cambium-cells, x 375. — After De Bary. 



forated horizontal or inclined septa (Fig. 74) ; in other 
forms they have fusiform extremities. 

(4. ) Tracheides. These consist for the most part of single 
closed cells, or of elements which closely resemble cells ; 



THE PRINCIPAL TISSUES. 85 

otherwise they possess the characters of vessels. In one form, 
as in the so-called wood-cells of Gymnosperms (see paragi'aph 
30, page 25) they resemble on the one hand the pitted ves- 
sels, and on the other the fibres of the wood of Angio- 
sperms. Every gradation between these tracheides and the 
other forms of tracheary tissue occur. In another form, as in 
Cytisus and Celtis, the tracheides are shorter than in tlie 
preceding, quite regular in their form, and with tapering 
extremities (Fig. 75). Their walls are but slightly thickened, 
and are marked with spirals and pits. When the wall be- 
tween two contiguous cells breaks through or becomes ab- 
sorbed the close relation of such tracheides to spiral vessels 
is readily seen. 

Tracheides may be regarded as composing a less differen- 
tiated form of tissue, related on the one hand to true tra- 
cheary tissue and on the other to fibrous tissue. 

{a) Specimens of spiral vessels with tlie spirals passing from riglit 
to left may be obtained by making longitudinal sections of tlie stems 
of Maha rotundifoUa, Impatiens Balsamina, and many other plants. 
If tlie thin slices are macerated in nitric acid and potassium chlorate 
the structure may be studied to still better advantage. The spirals in 
the vessels of Plnus syUestris pass from left to right ; they may be 
examined in longitudinal sections of the leaves or young twigs. The 
stems of Vitis mnifera, Berhei'is vulgaris, Bignonia capreolata, and Ar- 
temisia oMrotanum furnish examples of vessels, the first formed of 
which have their spirals running from right to left and the later ones 
from left to right. Interrupted spirals showing the two directions may 
be found in stems of CucurUta. 

(Ij) Examples of scalariform vessels may be obtained with the greatest 
ease from the rhizomes of ferns — e.g., of Pteris ; it may also be obtained 
from many Dicotyledons — e.g., the stems of Vitis. 

{c) Fine specimens of pitted vessels may be studied in longiiudinal 
sections of many kinds of wood — e.g., Pints, Quercus, and Liriodendroii ; 
among herbs, Impatiens and Bicinus furnish good examples. 

{d) In order to study the tracheides of the Gymnosperms thin slices 
of the wood — of Pinus, for example — should be heated for some time in 
nitric acid and potassium chlorate. By this means, after transferring 
to a glass slide and covering in the usual way, the tracheides may be 
easily isolated by gently tapping upon the cover-glass. 

{e) Tracheides of the second form are easily studied in horizontal and 
longitudinal sections of the wood of Oeltis. 



B6 BOTANY. 



§ III. The Primary Meristem.* 



109. — Under this name are grouped the unformed and 
growing tissues found at the ends of young stems, leaves, and 
roots. In these parts the tissues described above (paragraphs 
99 to 108) have not yet formed ; they are, on the contrary, 
composed entirely of a mass of thin-walled, growing, and 
dividing cells containing an abundance of non-granular pro- 
toplasm. In the lower plants the meristem-cells do not 
change much in their configuration or general structure as 
they develop into the ordinary plant-cells ; but the higher 
the type of plant, the greater are the changes which take 
place during the development of meristem into permanent 
tissues. 

110. — In most of the plants outside of the Phanerogams 
the primary meristem is the result of the continually repeated 
division of a single mother-cell situated at the apex of the 
growing organ. In the simplest forms this apical cell is the 
terminal one of a row of cells, as in many algse and fungi. 
The apical cell, in such cases, keeps on growing in length, 
and at the same time horizontal partitions are forming in its 
proximal portion. In this way long lines of cells may 
originate. 

In the more complicated cases the segments cut off from 
the apical cell grow and subdivide in different planes, so as 
to give rise to masses of cells. The partitions which succes- l 
sively divide the apical cell are sometimes perpendicular to 
its axis, but more frequently tiiey are oblique to it. In most £ 
mosses, for example (Fig. 76), the apical cell is a triangular, 
convex-based pyramid, whose apex is its proximal portion. "^'^ 
The successive segments are cut off from the apical cell by ^ ^^' 
alternate partitions parallel to its sides, thus giving rise to 
three longitudinal rows of cells. Most Pteridophytes have 
an apical cell not much different from that of the ma- 
jority of mosses. In Equisetimi, for example, it is an in- 
verted triangular pyramid, having a convex base (Fig. 77 ; P 

cor 

* From tlie Greek fiepo<i, part, and te/xvlev, to cut off. This tissue is Wjt 
eometimes called Proto-meristetn. jOj 



il 



PRIMARY MERISTEM. 



87 



A, side view, B, a section). The segments (daughter-cells) 
are cut off by alternating partitions parallel to the plane 
sides of the pyramid, as in the mosses. In some of the 
Bryophytes and Pteridophytes the apical cell is wedge-shaped 
— i.e., with only two surfaces — and in such cases two instead 
of three rows of meristem-cells are formed. 

111. — In the Phanerogams the Primary Mcristem is de- 
yeloped from a group of cells, instead of from a single one ; 
they therefore have no apical cell. This group of cells 




Fig. 76.— Loncjitudiiial section of apex of stem of a moss {Fontinalis antipyretica). 
', apical cell, forming segments (3 rows), each, segment divided into an outer cell, 
5, and an inner one— the former develops cortex of the stem and a leaf, the latter 
he inner tissue of the stem ; z, apical cell of lateral leaf-forming shoot, arising 
)eiow a leaf ; c, first cell of leaf ; &, cells forming cortex.— After Leitgeb. 

)ccupies approximately the same position in the organs of 
Phanerogams as the apical cell does in the Bryophytes and 
Pteridophytes ; it is composed of cells which have the power 
)f indefinite division and subdivision. 

112. — The apical cell, and its actively growing daughtei- 
ells in its immediate vicinity, or in the case of the Phanero- 
gams the apical group of cells, with their daughter-cells, 
onstitute the Growing Point or Vegetative Point {Punctum 
egetationis) of the organ. When this active portion is 
ionical in shape it is the Vegetative Cone of some authors. 



«8 



BOTANY. 



{a) Primary Meristem tissue may be readily obtained for study by 
mailing thin longitudinal sectious of the tips of growing sboots of 
Equiattitm, Phaseolus, Ilippuris, and the roots of Pteris, Zea, Impa- 
tiens, etc., or by carefully dissecting out the youngest rudiments of the 
leaves of many Monocotyledons. 

The value of the specimen will often be increased by staining it 
with carmine. 

(6) The apical cell, which may be seen in the best of the above-men- 



9-— i 





Fig 77.— The growing point of the stem of Equisetum scir2)oides. A, seen from 
wiihout, showing the apical cell at the top ; the numerals 1, 3, 4, etc., indicate the 
order of the formation of the partitions of the apical cell; that marked 1 is the last 
formed, 3 the third from the last, etc. ; between 4 and 7 on the right, and 6 and 9 on 
the left, are the partitions which form after the primarj-^ ones; B, a vertical section of ^. 

tioned sections of Equisetum and Pteris, should also be studied by 
making extremely thin cross-sections of the apical portion of the 
Vegetative Cone ; the triangular shape of the apical cell can thus be 
made out. 

The simple side view of the isolated Vegetative Cone is also instruct 
tive when so prepared that it can be rotated under the microscope. 



CHAPTER VII. 

TISSUE SYSTEMS. 

§ I. — The DiFFEEENTIATIOiT OF TISSUES INTO StSTEMSc 

113. — It rarely happens that the tissues which compose 
the body of a plant are uniform. In the great majority of 
cases the cells of the Primary Meristem become differently 
modified, so as to give rise to several kinds of tissues. The 
outer cells of the plant become more or less modified into a 
boundary tissue, and the degree of modification has relation 
to its environment. Certain inner cells, or lines of cells, be- 
come modified into sclerenchyma, or some other supporting 
tissue (collenchyma, or fibrous tissue), and here again there 
is a manifest relation to the environment of the plant. Cer- 
tain other inner cells, or rows of cells, become modified into 
tubes affording a ready means for conduction, and appear to 
have a relation to the physical dissociation of the organs of 
the higher plants, in which only they occur. Thus, in phy- 
siological terms, there may be a boundary tissue, a support- 
ing tissue, and a conducting tissue, lying in the mass of less 
differentiated ground tissue. 

114. — In different groups of plants the elementary tissues 
described in previous paragraphs (99 to 108) are aggregated 
in different ways, and are variously modified to form these 
bounding, supporting, and conducting parts of the plant. 
Several tissues, or varieties of tissue, are regularly united or 
aggregated in particular ways in each j^lant, constituting 
what may be called Groups or Systems of Tissues. A Tis- 
sue System may then be described as an aggregation of ele- 
mentary tissues, forming a definite portion of the internal 
structure of the plant. From Avhat has already been said, it 



90 



BOTANY. 



is clear that systems of tissue do not exist in the lowest 
plants, and that tliey reach their fullest development only 
In the liighest orders. It is evident also that these systems 
have no existence in the youngest parts of plants, but that 
they result from a subsequent development. 

115. — Many systems of tissue might be enumerated and 
described ; but here again, as with the elementary tissues, 
while there are many variations, there are also many grada- 
tions, having on the one hand a tendency to give us a long 
list of special forms, and on the other to reduce them to one, 
or at most to two or three. The three systems proposed 
by Sachs are instructive, and will be followed here ; they 
are : (1) the Fundamental System, which includes the mass 
of unmodified or slightly modified tissues found in greater or 
less abundance in all plants (except the lowest) ; (2) the 
Epidermal System, composed mainly of the boundary cells 
and their appendages (hairs, scales, stomata, etc.) ; (3) the 
Fibro-vascular System, comprising those varying aggrega- 
tions of tissues which make up the string-like masses found 
in the organs of the higher plants. 



§ II. — The Epideemal System of Tissues. 

116 — This is the simplest tissue system, as it is the ear- 
liest to make its appearance, in passing from the lower forms 
to the higher. It is also (in general) the first to appear in 
the individual development of the plant. It is sometimes 
scarcely to be separated from the underlying mass, as in 
most higher Thallophytes and Bryophytes ; and here it is 
composed of but one tissue — parenchyma — or of two or more 
slight variations of it. In Pteridophytes and Phanerogams, 
while it may be very simple in some (aquatic) plants, it fre- 
quently attains some degree of complexity, and is sharply 
separated from the underlying ground tissues. 

117. — In the simpler epidermal structures of the Thado- 
phytes the cells are generally darker colored, smaller, and 
more closely approximated than they are in the subjacent 
mass ; in some higher fungi a boundary tissue may be easily 
separated as a thickish sheet, but probably in such case a 



THE EPIDERMAL SYSTEM. 



91 



portion of the underlying mass is also removed. In many 
of the Thalloj^hytes there is absolutely no differentiation of 
an epidermal portion. 

118. — In the Bryophytes there is in general a poor epider- 
mal development ; it is composed for the most part of one 
or more weakly defined layers of smaller cells, which, how- 
ever, pass by insensible gradations into the inner tissue 
mass. Here, however, the first true epidermal hairs make 
their appearance. 

119. — In one group of the Liverworts — the MarchantiacecB 




Fig. 78.— Longitudinal section of erect portion of thallus of Marchantia polymor- 
pha. 0, epidermis ; S, walls between air-spaces, the latter filled with rows of chloro- 
phyll-bearing cells, chl ; sj), a stoma ; g, a large parenchyma-cell, x 550.— After Sachs. 



— there is an epidermal system of a high degree of perfection, 
and composed of epidermis proper and stomata (Fig. 78). 
The epidermis consists of a single layer of somewhat tabu- 
lar cells arching over the air-cavities which occupy the upper 
surface of the plants ; it is perforated here and there by sto- 
mata or breathing pores, composed of four to eight circular 
rows of cells placed one above the other {sp in the figure). 
These chimney-like structures originate by the division of a 
single cell into four or six radiating daughter-cells ; in the 
centre of this group an intercellular pore is formed by the 
lateral growth of the cells (Fig. 79) ; and by a subsequent 



92 



BOTANY. 



horizontal division the several superimposed circular rows 
of cells are formed. 

120. — In true mosses the sporangia possess an epidermal 
system which is composed of a layer of strongly cuticular- 
ized cells — the epidermis — sometimes provided with stomata. 
Other portions of the plant, aside from the sporangia, are 
destitute of a true epidermis or of stomata. 

121. — The epidermal systems of Pteridophytes and Phaner- 
ogams are so much alike that they may be described together, 
although it must be remembered that in the latter group 
they are, in general, somewhat more perfect than in the for- 
mer. In these groups the epidermal 
structures consist usually of three por- 
tions : (1) a layer of more or less 
modified parenchyma — the epidermis 
proper — bearing two other kinds of 
structures which develop from it, viz., 
(2) trichomes, and (3) stomata. 

122.— Epidermis. The differentia- 
tion of parenchyma in the formation 
of epidermis, when carried to its ut- 
most extent, involves three different 
modifications of the cells, viz., (1) 
change of form, (2) thickening of the 
walls, (3) disappearance of the proto- 
plasmic contents. These three modi- 
fications may occur in varjang de- 
grees of intensity ; they may all be slight, as in many aquatic 
l^lants and in the young roots of ordinary plants ; or the cells 
may change their form, while there may be little thickening 
of their walls, as in other aquatic plants, and some land plants 
which live in damp and shady places ; or on the other hand, 
the change of form of the cells may be but little, while 
their walls may have greatly thickened, resulting in a disap- 
pearance of their protoplasm, as may be seen in parts of 
some land plants which grow slowly and uniformly. When 
the differentiation of epidermis is considerable, it can usu- 
ally be readily removed as a thin transparent sheet of color- 
less cells. 




Fig. 79.— Top view of two 
stomata of 3Iarchantia poly- 
mo7^ha. B. young stoma ; 
si, guard cells ; C, older sto- 
ma, in which the pore or 
opening, jio, is much larger ; 
si, guard-cells —After Sachs. 



THEj EPlDEBMJLda fJlTJ2'Mm. 93 

123. — The change in tho fonn of tlhio epidermal cells is 
due to the mode of growth of the organ of which they form 
a part ; the lateral and longitudinal growth of an organ 
causes a corresponding extension and consequent flattening 
of the cells ; if the growth has been mainly in one direction, 
as in the leaves of many Monocotyledons^ and the young 
• shoots of many Dicotyledons, or if the grov^th in two direc- 
tions has been regular and uniform, as in the leaves of some 
Dicotyledons, the cells are quite regular in outline ; where, 
however, the growth is not uniform the cells become irregu- 
lar, often extremely so (Fig. 89, page 100). 

124. — The thickening of the walls is greatest in those 
plants and parts of plants which are most exposed to the dry- 
ing effects of the atmosphere. It consists of a thickening of ■ 
the outer walls, and frequently of the lateral ones also. The 
outer portion of the thickened walls is cuticularized, and 
this, by a subsequent stratification and lamellation, is separ- 
ated as a continuous pellicle, the so-called cuticle. 

125. — The cuticle extends uninterruptedly over the cells, 
and may be readily distinguished from the other portions 
of the outer epidermal walls. It is insoluble in concen- 
trated sulphuric acid, but may be dissoh^ed in boiling 
caustic potash. Treated with iodine it turns a yellow or 
yellowish brown color. A waxy or resinous matter is fre- 
quently developed upon the surface of the cuticle, constitut- 
ing what is called the bloom of some leaves and fruits. De 
Bary* distinguishes four kinds of waxy coating, as follows : 
(1) continuous layers or incrustations of wax — e.g., on uie 
leaves and stems of purslane, the leaves of Fuchsia, yew, the 
stems of the wax palms {Ceroxylon), etc. ; (2) coatings com- 
posed of multitudes of minute rods placed vertically side by 
side upon the cuticle — e.g., on the stems of sugar cane, 
Coix lachryma, and some other grasses ; (3) coatings made 
up of minute rounded grains in a single layer — e.g., on the 
leaves of the cabbage, onion, tulip, clove-pink {Dianthus 

* " Vergleicliende Anatomie der Vegetationsorgane der Phaneroga- 
men und Fame," 1877, p. 87, where figures of several of these kinds 
are given. 



94 BOTANY. 

Caryopliyllus), etc. ; (4) coatings of minute needles or grains 
irregulurly covering the surface with several layers — e.g., on 
the leaves of Eucalyptus globulus, rye, etc. 

126. — The protoplasm of the epidermal cells generally 
disappears in those cases where there is much thickening of 
the walls ; it is always present in young plants and parts of 
plants ; it is also frequently present in older portions, which 
are not so much exposed to the drying action of the atmos- 
phere, as in roots, and the leaves and shoots of aquatic plants, 
and of those growing in humid places. In few cases, how- 
ever, are granular protoplasmic bodies (e.g., chlorophyll) pres- 
ent in epidermal cells. * 

127. — While the epidermis always consists at first of but 
one layer of cells, it may become split into two or more lay- 
ers by subsequent divisions parallel to its surface. These 
layers may resemble the outer one and have their walls 
thickened, as in the leaves of the Oleander, or they may con- 
sist of thin-walled cells with watery contents (constituting 
the so-called Aqueous Tissue), as in the leaves of Ficus and 
Begonia. 

(a) Epidermis may be studied witli comparatively little difficulty. 
In many cases it may be stripped off in thin sheets and mounted in 
tlie usual way; such preparations, with thin cross-sections (which are 
readily made by placing a piece of leaf between pieces of elder pith), 
are sufficient, in most cases, to give a good knowledge of the structure. 
The leaves of many Liliacece (hyacinths, lilies, etc.) and Graminece may 
be examined for regular cells, and those of many Dicotyledons, as bal- 
sams, primroses, and fuchsias, for irregular ones. 

(5) Thickened epidermal walls may be found in leaves of a hard tex- 
ture, as those of the pines, holly, oleander, mistletoe, many CompositcB, 
and in the stems of many Cactacem. The stratification of the thickened 
walls may be brought out in the cross-sections by heating in a solution 
of potash. 

(c) A series of specimens of the epidermis, taken from leaves of all 
ages, from their youngest and smallest rudiments in the bud up to full- 
grown ones, is instructive. 



* In the leaves of Primula sinensis, grown in the green -house, the 
epidermal cells contain many chlorophyll-bodies ; the leaves of Fuchsias, 
under similar conditions, possess a few chlorophyll-bodies in the epider- 
mal layer. 



THE EPIDERMAL SYSTEM. 



95 



128.— Trichomes. Under this term are to be included the 
outgrowths which arise from the epidermis ; they may have 
the form of hairs, scales, glands, bristles, prickles, etc., and 
may be composed of single cells, or of masses of cells. 

They originate mostly from the growth of single epidermal 
cells,* and on their first appearance consist of slightly en- 





Ife- 



Fig. 81. 



Fig. 80.— Transverse section of epidermis and underlying tissue of ovary of Cu' 
cnrhita. a, hair of a row of cells ; b and d, glandular hairs of different ages; e,f 
chairs in the youngest stages of their development. X 100.— After Prantl. 

Fig, 81. — A seedling mustard plant with its single root clothed with root-hairs? 
the newest (lowermost) portion of the root is not yet provided with root-hairs, 

larged and protruding cells (Fig. 80, e, f, c). These may 
elongate and form single-celled hairs, which may be simple 
or variously branched. The most important of these hairs 
are those which clothe so abundantly the young roots of most 
of the higher plants, and to which the name of Root-hairs 



* It is probable that the common statement that trichomes alveays 
develop from single cells must be modified. 



96 



BOTANY, 



has been applied (Fig. 81). These are composed of single 
cells, which have very thin and delicate Avails (Fig. 82), and 
are the active agents in the absorption of nutritive matters 
for the plant. 




Fig. 82.— Eoot-hairs of a seedling rye plant. A, the ends of three hairs, one much 
emaller th in the others ; the larger ones have particles of sand adhering to and im- 
bedded in iheir walls ; B^ the base of a hair growing from the rooi-cell, r. X 900. 

129. — In the development of the hairs on aerial parts of 
plants it frequently happens that the terminal cell becomes 
changed into a secreting cell, in which gummy, resinous, or 
other substances are produced ; sometimes several terminal 



THE EPIDERMAL S18TEM. 



cells are so transformed into a secreting organ, 
tion appears as a rounded 
pustule, partly surround- 
ing the secreting cell 
(Figs. 83 to 87), and 
which is removed upon 
the slightest touch. Tri- 
chomes of this nature are 
called glandular hairs ; 
they are exceedingly vari- 
able in form, and are not 
infrequently short and 
depressed, when they are 
known as surface glands, 
or glandular scales (Fig. 
87). 



The secre- 




Fig. 83.— Glandular hairs from the petiole of 
Primula sineiisis, in several stages of develop- 
ment, a, the beginning of the secretion in the 
terminal cell ; b, hair with a large mass of se- 
creted matter ; d, an old hair after the removal 
of the secreted matter, x 142.— After De Bary. 



(a) Tricbomes are, in gene- 
ral, easy objects of study. 
In many cases tbey may be 
simply scraped off and mounted in alcobol, or in a solution of potash 




Fig. 84. 



Fig. 85. 



Fig. 86. 



Fig. 87. 



Fig. 84. —a', the cell a of Fig. 83 more highly magnified ; a'' the same after removal 
of the secretion by treatment with alcohol, x 375.— After De Bary. 

Fig. 85.— c, end of a hair with large mass of secreted matter ; c', the same after 
treatment with alcohol, x 375.— After De Bary. 

Fig. 86.— The end of the hair d, in Fig. 83, more highly magnified, showing the frag- 
ments of the secretion pnstulc surrounding the terminal cell, which still contains pro- 
toplasm. X 375 —After De Bary. 

Fig. 87.— Glandular scale from the hop. A, in its young stage ; B, the same some 
time afterward— the secretion from the cells has pushed out the cuticle and filled the 
Bpace between it and the cells (in the specimen from which these were drawn the 
secretion was removed by solution in alcohol), x 142.— After De Bary. 

after wetting them witb alcobol to free tbem from entangled and en- 
closed air. 



98 



BOTANY 



{h) One-celled simple bairs may be obtained from tlie vegetative 
organs of species of (Enothera and Brassica and many fjrasses — e.g., 
species of Panicum — and from the seeds of the cotton plant ; the last 
constitute the " cotton" of commerce. 

(c) Many-celled simple hairs occur on the filaments of Tradescantia, 
on leaves of the Primrose, Ageratum, Erigeron Canadense, pumpkin, 
and very many others. 

id) Branched one-celled hairs occur in Gapsella, Draha, Sisymhryum, 
Alyssum, and many other Cruciferm. 

(e) Branched many-celled hairs may be found on the Mullein and 
Ivy. 




Fig. 88.— Hairs from Thistle {Cniais altissimiis). a, young hair from the stem 
before it has been drawn out ; B^ an older hair more highly magnified, after its ex- 
tremity has been drawn out into a thread-like lash ; C, hair with a long lash from 
the underside of a full-grown leaf. Highly magnified.— After Beal. 

(/) Clustered or tufted hairs are found on many Malvacece, and the 
nearly related scales or peltate hairs on Shepherdia. 

(g) Root-hairs are best obtained for study by growing seeds of mustard, 
radish, vrheat, etc., on damp cotton or blotting'-paper, and then mak- 
ing careful longitudinal sections of the terminal portion of the root at 
the place where the hairs are just appearing (usually several millimetres 
above the tip of the root). By making preparations in this way all 
stages of the development of these hairs may be studied in the same 
specimen. 

(h) Glandular hairs are found in many groups of plants ; they may 
be studied in Petunia, Verbena, Primula, Martynia, and the tomato. 

(i) Apparently related to glandular hairs are the curious hairs from 



THE EPIDERMAL SYSTEM. 99 

whicli, as pointed out by Professor Beal,* are drawn out tlie long 
thread-like lashes which are so abundant on the leaves of some thistles 
and other Compositm (Fig. 88). These lashes appear to be of the na- 
ture of secretions, and they are capable of being drawn out to an aston- 
ishing length. These are, in turn, much like the glandular hairs on 
the leaves of Dipsacus sylnestris, discovered by Francis i)arwin,f 
and from which motile protoplasmic filaments protrude. Mr. Darwin 
concludes that they have the power of absorbing nitrogenous matter. 

130. — Stomata (singular, Stoma). These structures cqu- 
sist, in most cases, of two specially modified chlorophyll- 
bearing cells, called the G-uard-cells, which haye between 
them a cleft or slit passing through the epidermis (Figs. 89, 
90). These openings are always placed directly over interior 
intercellular spaces. Stomata are developed from, and in 
their distribution always have a relation to, the epidermal 
cells ; in an epidermis composed of regular cells there is 
more or less regularity in the arrangement of the stomata ; 
but when the epidermal cells are irregular the stomata are 
also irregularly placed. 

They occur on aerial leaves and stems most abundantly, 
being sometimes exceedingly numerous, and are exception- 
ally found on other parts, as the sepals, petals, and carpels 
of the flowers. On submerged or underground stems and 
leaves they are found in less numbers, and from true roots 
they are always absent. The stomata on leaves are generally 
confined to the lower surface, and when present on the up- 
per they are usually much fewer in number ; there are, how- 
ever, some exceptions to this. 

131. — Their development generally takes place in the fol- 
lowing way : in a young epidermis-cell a partition forms at 
right angles to the plane of the epidermis, cutting off a por- 
tion of the cell : this in one series of cases becomes the 
mother-cell of the stoma ; in another series of cases, how- 
ever, it is divided one or more times by subsequent partitions 
before the mother-cell is formed. In either case, when once 

* In an article entitled "How Thistles Spin," in the American Nat- 
uralist, 1878, page 643. See also an article by the satne writer on 
*• Hairs and Glandular Hairs of Plants : their Forms and Uses," in the 
same volume of the journal named, on page 271. 

f See his account, with a plate, in Qr. Jour, of Mic. Science, 1877, p. 245. 

Lorc. 



100 



BOTANY. 



^ ^ s- 



the mother-cell is formed a median partition -wall forms 
in it, and gradually becomes separated into two plates, which 

eventually sepa- 
rate and form a 
pore through 
the epidermis. 
The two halves of 
the mother-cell be- 
come symmetrical- 
ly rounded off into 
semilunar or semi- 
circular forms, 
and constitute the 
guard-cells before 
mentioned. The 
details of the fore- 
going process in 
one of its more 
^ , complex forms 

Fig. 89.— Stomata from the under surface of the leaf of . i_ i. j • 

Echinocystis lobata. s, s, stomata ; g, g, irregular epider- are lliustrateu m 

mis-cells between the veins of the leaf ;«, elongated and j-,. cii A ^ Z? 

regular epidermis-cells over a vein. X 250.— From a J^ Ig. ^i-, -^ anCt J5. 

drawing by J. C.Arthur. rpj^^ Splitting of 

the middle partition-wall of the mother-cell is shown in the 
successive sections (Fig. 9^). 

132. — In the light, under certain conditions of moisture 
and temperature, the 
guard-cells become 
curved away from each 
other in their central 
portions, thus opening 
the slit and allowing 
free communication 
between the external 
air and that in the in- 
tercellular spaces and 
passages of the leaf. 





WUJ( 




Fig. 90.— Double stomata from the under surface 
of the leaf of Echinocystis lobata, X 500.— From a 
drawing by J. C. Arthur. 



{a) A superficial examination of stomata may be easily made 1)/ 
stripping off the epidermis, and mounting it in water or alcohol. Good 
sections of stomata are more difl5cult to make ; they may bj obtained, 



101 




"Pig. 91.— The development of the Ptomata of the leaf of Sedum purpiiraseens. A, 
apieceof very young epidermis, showing the early stages of the process. The nu- 
inerala indicate the order of formation of the partitions ; that marked 1, 1, 1, was 
lormed first, then 2, 2, and last 3, 3 ; the cell enclosed by these three partitions is the 
stoma-mother-cell ; B, a fully completed stoma ; e, e, two original epidermis-cells— 
in the right hand one the new partition 1, 1, 1, first appeared ; this was followed by 
2, 2, 2, then by 3, 3, and 4, 4 ; '^stly the cell thus formed became divided by a middle 
partition, which soon solit, and thus formed the opening of the stoma.— After Sachs. 




Fig. 92d. Fig. 92e. 

Fig. 92.— Development of thes^-omata of the leaf of Hyacinthus orientalis, eeen ia 
transverse section. A, the division of the mother-cell S; e, e, epidermlH-cclis ; p p, 
parenchyma-cells ; i, small intercellular i-i)ace ; B and C\ the same a little later ; />, 
first separati(m of the two gnard-cells by the splitting of the partition between them, 
forming the opening t ; E, the fully formed stoma, x 800.— Aiter Sachs. 



102 



BOTANY, 



however, by makinfr a large number of very tliin sections of the whole 
leaf (by placing it between two pieces of elder pitli), when it will be 
found that in some cases stomata have been cut through in the man- 
ner shown in Fig. 92. 

(&) Examples may be obtained from any of tlie higher plants, but 
those which are of a firm texture and have a smooth epidermis are 
best to begin with — e.g.,i\\e hyacinth, tulip, the lilies, many grasses, 
fachsia, lilac, etc. 

(c) Weiss* determined the number of stomata on the epidermis of 
both surfaces of 167 leaves of plants ; some of his results are given 
below : 



Olea Europea 

Vinca minor 

Juglans nigra 

Ailanthus glandulosa 

Syringa vulgaris 

Helianthus annuus 

Brassica oleracea 

Platanus occidentals 

Populus dilatata 

Solanum dulcamara 

Euphorbia cyparissias 

Madura aurantiaca 

Betula alba 

Berberis vulgaris 

Pisum sativum 

Buxus sempervirens 

Prunus Mahaleb 

Asclepias incarnata 

Datura stramonium 

Taxus baccata , . . . 

Zea mais 

Chenopodium ambrosioides.. 

Ficus elastica 

Ribes aureum 

Populus monilifera o . . 

Pinus sylvestris 

Anemone nemorosa 

Lilium bulbiferum 

Iris Germanica 

Avena sativa 



In one square millimetre. 


In one square inch. 


Upper side. 


Under side. 


Upper side. 


Under side. 





625 





403,135 





477 





308,665 





461 





298,345 





386 





248,970 





330 





212,850 


175 


325 


112,875 


209,625 


138 


302 


88,910 


194,790 





278 





179,310 


55 


270 


35,475 


174,150 


60 


263 


38,700 


169,635 





259 





167,055 





251 





161,895 





237 





152,865 





229 





147.705 


101 


216 


65,145 


139,320 





208 





134,160 





204 





131,580 


67 


191 


43,215 


123,195 


114 


189 


73,530 


121,905 





166 





107,070 


94 


158 


60,630 


101,910 


184 


156 


118,680 


100,620 





145 





93,525 





145 





93,525 


89 


131 


57,405 


84,495 


50 


71 


32,250 


45,895 





67 





43,215 





62 





39,990 


65 


58 


41,925 


38,410 


48 


27 


30,960 


17,415 



*In a paper on the Number and Size of Stomata, published in 
Pringsheim's " Jahrbiicher fiir Wissenschaftliche Botanik," 1865. 



THE EPIDERMAL SYSTEM. _ 



(d) In the plants lie examined he found that there were 



103 



= 645 to 64,500 per sq. inch 

= 64,500 to 129,000 " 

= 129,000 to 193,500 " 

= 193,500 to 258,000 " 

= 258,000 to 322,500 " 

= 322,500 to 387,000 " 

= 387,000 to 451,500 " 

(e) Morren's measurements* vary somewhat from those given by 
Weiss. The following, not given by Weiss, are taken from Morren's 
table : 



54 species 


witli from 1 to 100 sto 


tnata per sq. mm 


38 " 


<( 


100 to 200 


" " " 


89 « 


" 


200 to 300 


( (( (( 


12 " 


" 


300 to 400 


( (( (( 


9 " 


" 


400 to 500 


i U <4 


1 " 


" 


500 to 600 


{ a u 


3 " 


" 


600 to 700 


' " " 





In one square millimetre. 


In one square inch. 




Upper side. 


Under side. 


Upper side. 


Under side. 


Trifolium pratense 

Humulus Lupulus 


207 






75 



49 


335 

256 

253 

246 

196 

155 

115 

91 

86 

42 


133,515 






48,375 



31,605 


216,075 
165,120 


Prunus domestica 


163,185 
158,670 
126,420 
99,975 
74,175 
58,695 
55,470 
27,090 


Pirus Malus 


Hedera helix 


Vitis vinif era 


Beta vulgaris ... 

Pirus communis 


Philadelphus coronarius 

Secale cereale 



(/) The stomata of the so-called Compass Plant {Silphium lacinia- 
tum) are nearly equal in number on the two sides of the vertical leaves ; 

! there are on the true upper surface 82 per sq. mm, {— 52,700 per sq. 

jl inch), and on the under surface, 87 per sq. mm. (= 57,300 per sq. 
inch).f 

{g) On most leaves the stomata are not distributed equally over all 

I portions of either surface ; they are not found on the veins, but are 

I restricted to the areas between them. In some plants this restriction 
is accompanied by a further modification, as in Geanothus prostratuSf 
where the stomata are confined to the bottoms of sunken pits which 

; occur on the under side of the leaves. In the long harsh leaves ol 
Stipa spartea the stomata of the upper surface are restricted to the 
sides of the deep longitudinal channels which lie between the promi- 
nent nerves. (See Figs. 135-6, page 158.) 



* Published first in BvZletin de VAcademie royale de Belgique, vol. 
16, number 12, 1864, and also in part in Pringsheim's " Jahrbiicher," 
i etc., 1. c. 

l f See an article in American JSfaturalist, 1877, p. 486 : *' Observations 
I; on Silphium laciniatum, the so-called Compass Plant," by C. E. Bessey; 



104 



BOTANY. 



{h) Water-pores. De Bary* describes under this name some curious 
stoma-like structures which occur on many plants. These, instead of 
containing air in their cavities, normally contain water. Their guard- 
cells, which are, in some cases at least, much like those of ordinary 
stomata, are immovable, and as a consequence the pore is incapable of 
enlargement or contraction. They are always found over the ends of 
small bundles of spiral vessels, which appear to pass into the pore cav- 
ities. 

One form of these may be readily examined in the leaves of the f uch- 




Fig. 93. 



Fig. 94. 



Fig. 93.— Surface view of the water-pore on the extremity of the leaf-tooth of Fuch- 
sia globosa. X 500.— After Arthur. 

Fig. 94.— Transverse section of leaf-tooth of Fuchsia globosa; cp, chlorophjil- 
bearmg parenchyma, within which is the fibro-vascular bundle ; ra, raphis-cells. X 
125.— After Arthur. 

sia, and the primrose {Primula sinensis). In the fuchsia they are found 
in the papillae or small teeth on the margins of the leaves, and in ihe 
primrose, in the papillae terminating the lobes and lobules. In Fuchda 
globosa each leaf-tooth is provided with a single terminal pore (in some 
of the dark colored varieties there are several), which resembles an 
ordinary stoma (Fig. 93). Beneath the pore is a cavity, commonly filled 
with water (Fig. 95, &), which, by evaporation, deposits calcium car- 
bonate upon the walls of the lining cells, thereby discoloring them. A 
fibro-vascular bundle is continued from the veins of the leaf through 

* In '* Vergleichende Anatomie der Vegetation sorgane," etc., 1877, 
on page 54, et sea. References are there given to the literature of the 
subject, which is both recent and limited. After Mettenius' paper in 
Filices Jiorti Lipsiensis, others appeared by other writers in Botanische 
ZeUung, 1869, 1870, and 1871. 



THE EPIDERMAL SYSTEM. 



105 



the tooth to the water-cavitj ; in the tooth it becomes greatly enlarged, 
and is there composed of spiral cells (tracheides), which surround a 
central mass of narrow elongated parenchymatous cells (Fig. 95, c, g\ 
The bundle terminates by the free ends of the parenchyma-cells extendi 




Fig. 95.— Vertical section of a leaf-tooth of Fuchsia gldbosa. a, vertical longitudi- 
Qal Bection of water-pore ; b, water-cavity ; c, tracheides ; d, chlorophyll-bearing 
parenchyma ; e, large cell containing raphides ; /, hair ; g, parenchyma of the fibro- 
v^ascular bundle. The lower part of the figure passes into the leaf-blade, x 125.— 
A.fter Arthur. 

ing loosely into the water-cavity. Between the bundle and the epider- 
mis of the leaf-tooth lie two or three cell layers of ordinary chlorophyll- 
bearing parenchyma, in which there are occasionally large cells con- 
taining raphides (Fig. 94, cp and r«).* 

* The foregoing account of the water-pores of FacJisla glohosa, and 
the drawings for Figs. 93-4-5, nre taken from an unpublished paper 
on "The Water-Pores of FucJisia f/loho^a,'" by J. C. Artlm'- 



106 BOTANY. 

Water-pores nearly like those of tlie fuchsia occur on some species of 
Saxifraga, Ileuchera, Mitella, Aconitum, DelpMnium, Sambucus, and 
many other plants. 

Another form, more closely resembling the ordinary stomata (but of 
much larger size), occurs on Tropmolmn Ldbbianum, RocJiea cocdnea, 
and others. 

§ III. The Fibro-vasculak System. 

133. — In most of the higher plants portions of the pri- 
mary meristem early become greatly differentiated into 
firm elongated bundles, which traverse the other tissues. 
They are composed for the most part of tracheary, sieve, 
and fibrous tissues, together with a varying amount of pa- 
renchyma. These elementary tissues have, with some con- 
siderable variations in the different groups of plants, a gen- 
eral similarity of arrangement and aggregation throughout 
the Pteridophytes and Phanerogams. In a comparatively 
small number of cases laticiferous tissue is associated with 
the above-mentioned tissues. To these aggregations of tis- 
sues the name of Fibro-vascular Bundles has been given.* 

134. — In many plants the fibro-vascular bundles admit of 
easy separation from the surrounding tissues ; thus in the 
Plantain {Plantago major) they may readily be pulled out 
upon breaking the petioles. In the leaves of plants, where 
they constitute the framework, they are, by maceration, 
readily separated from the other tissues as a delicate net- 
work. In the stems of Indian corn the bundles run through 
the internodes as separate threads of a considerable thick- 
ness. 

135. — It is impossible to fix upon a particular form as the 
type of the fibro-vascular bundle. It should be understood 
at the outset that the similarity between the bundles of 
widely sejoarated groups of plants is only a general one, and 
that there are great differences in the details of their struc- 
ture. It must further be borne in mind that these bundles 
are not themselves tissues, but aggregations of dissimilar tis- 

* They are also called Vascular Bundles ; this term ought, however, 
to be retained for those reduced bundles in which only vessels are pres- 
ent — e.g., in the veinlets of leaves. 



I 



THE FIBRO-VASCULAR SYSTEM. 



10? 



sues, any of which may be wanting in, or separated a little 
space from, the bundle. In short, the elementary tissues, 
particularly tracheary, sieve, fibrous, and parenchymatou? 
tissues, are to be considered as the units, and the term Fibro- 
yascular Bundle as little more than a convenient expression 
of the usual condition of aggregation of these units. * 

The general structure of fibro-vascular bundles will be 
more readily un- 
derstood after 
the examination 
of a number of 
examples. Those 
which follow are 
not in any sense 
typical ; they are 
only illustrative. 

136.— The fi- 
bro-vascular bun- 
dle of the stem of 
Pteris aquilina 
is composed of 
tracheary and 
sieve tissues, par- 
enchyma, and a 
small amount of 
poorly developed 
fibrous tissue. In 
transverse s e c - 
tion the bundle 
has usually an 
elliptical outline. 
The great mass 
of the bundle is made up of large scalariform vessels, 
which occupy its interior (g, g, g, Eig. 96). Enclosed in 
the scalariform tissue are masses of parenchyma and a few 

* By considering the Fibro-vascular Bundle to be one of the struc- 
tural units of tlie higlier plants a serious mistake lias been made, 
leading to j)rofiiless discussions and speculations as to its typical struc- 
ture, and diverting- attention from the study of its actual structura 




Part of a transverse section of the fibro-vas- 
cular bundle of the stem of Pleris aqinlina ; s, spiral ves- 
sel ; ff, g, scalariform vessels ; .«/>, sieve tissue; i*, fibrous 
tissue ("protophloem of Russow) ; sg, bundle sheath; p, 
starch-bearing parenchyma : K, K, thickened angles of 
scalariform vessels. — After Sachs. 



108 



BOTANY. 



spiral vessels, tlie latter occurring near tlie foci of tlie el- 
liptical cross-section of the bundle {s, Fig. 96). Surround- 
ing, or partly surrounding, the tracheary portion of the bun- 
dle is a layer of sieve tubes {sj), Fig. 96), separated from the 
large scalariform vessels by a layer of parenchyma. Outside 
of the sieve tissue is a mass of fibrous tissue {jb, Fig. 96), 
which is itself bounded externally by another layer of paren- 
chyma. The whole bundle is surrounded by a layer of paren- 




_Fig. 97.— Transverse section of the fibro-vascnlar bundle of the rhizome of PolypO' 
avwm vulgare ; sp, sp, Darrow spiral vessels in the edge of the mass of scalariform ves- 
sels ; s, region of the sieve tissue filled with parenchyma and poorly developed sieve 
tissue ; u, bundle sheath, outside of which is parenchyma, X 225.— After De Bary. 

chyma differing from the other parenchymatous tissues in 
not containing starch in its cells ; to this the name of Bun- 
dle Sheath has been given. 

A noticeable feature in the structure of this fibro-vasculai 
bundle is that the tissues have a concentric arrangement ; 
the tracheary tissue is encircled by a layer of parenchyma ; 

See, in tliis connection, an article on " Some recent views as to tlie com- 
position of the Fibro-vascular Bundles of Plants," by S. H. Vines, in 
Qr. Jour. Mlc. Science, 1876, ry. 388. 



THE FJBRO-VASGULAR SYSTEM, 



109 



this by one of sieve tissue ; this again by fibrous tissue, and 
so on. 

137. — A similar but not identical structure is found in the 




Fig. 98.— Part of the cross-section of an old root of Adianlum Moritzianum. h^ h. 
hairs of the root surface ; u,u, bundle sheath (endodermis) ; between h and w, pa- 
renchyma ; pc, pericambium ; pr, a plate of tracheary tissue, which is bounded on 
each side by sieve tissue, X 235.— After De Bary. 

bundle of the rhizome of Polypodium vulgare. Here the 
central portion of the stem is made up of scalarif orm tissue 
(Fig. 97, the larger, thicker-walled tissue), and this is sur- 
rounded by a tissue which may be regarded as but partly 



no 



BOTANY. 



differentiatecl, being composed of parenchyma and poorly 
developed sieve tubes {s, Fig. 97). The whole bundle is sur- 
rounded, as in Pteris aquilma, by a bundle sheath (ii, Fig. 
97). In the outer part of the mass of scalariform tissue are 
a few narrow spiral vessels {sp, sp. Fig. 97), but they are 
not sufficiently numerous to constitute a ring or layer. 
138. — In the root of Adiantum Moritzianum the bundle 

consists of a cen- 
tral plate of tra- 
cheary tissue (^r, 
Fig. 98), with a 
mass of sieve 
tissue on each 
side of but not 
quite enveloping 
it. Next outside 
of this is a layer 
of active paren- 
chyma, the peri- 
cambium {pc, 
Fig. 98), and sur- 
rounding the 
whole is a poorly 
developed bundle 
sheath («, Fig. 
98). 

139. — In the 
stem of Equise- 

Fig. 99.— Transverse section of a fibro-vascular bundle of , 7 / . ' {■ 

Equlsetnmpalustre. r, ^, ringed vessels on the border of a tUlll pdlUSXTQ ID 

large intercellular canal; «, sieve tissue; g,g, groups of • ^ ^ 

annular and reticulated vessels; w, the so-called general -"^^ i^^ih fcu casj t.a 

bundle sheath, which surrounds all the bundles; i, i, axial \^ \\\c, fnrAo-nino' 

air can Js; x , x , fragments of the ruptured cells. X 145. ^^^ ^"^ xuic^uiii^ 

^After De Bary. (.^ges to mark the 

limits of the bundles, which are arranged in a circle about 
the axis. * On the axial side of each bundle there are at 
first a few spiral and annular vessels, most of which, 
along with a considerable amount of parenchyma, are 

* In Equisetum Umosum, however, there is a bundle sheath about 
each bundle, consequently there is in that species no difficulty as t<f 
the limits of the bundle. 




THE FIBBO-VASCULAB SYSTEM. 



Ill 



destroyed shortly after their formation, thus forming a 
wide canal (Fig. 99; t, spiral, and r, annular vessels 
on the border of the canal). Immediately in front of or 
outside of the canal is a considerable mass of sieve tissue, 
made up of true sieve tubes and the nearly allied cambiform 
or latticed cells 
{s, Fig. 99). 
Eight and left of 
the sieve tissue 
lie a few annular 
and reticulated 
vessels {g, g, Fig. 
99). Exterior to 
all the bundles 
(in this species) 
is a cellular lay- 
er, which, has re- 
ceived the name 
of bundle sheath, 
but which, prob- 
ably, has no rela- 
tion to the lay- 
er so named that 
surrounds each 
fibro - vascular 
bundle of some 
plants. 

140. — The 
structure of the 
bundle in Selagi- 
nella incequifolia 
bears a consider- 
able resemblance 
to that of Pteris aquilina. There is in each bundle a 
central plate of tracheary tissue, consisting of a few narrow 
spiral vessels in its two edges and a remaining mass of scala- 
riform vessels (Fig. 100). The tracheary portion is sur- 
rounded by a tissue of elongated, thin-walled tissue which 
is, at least in part, a sieve tissue. In this and allied species 




V\g. 100.— Cross-eection of the stem of Selaginella incequi- 
folia, showing three bundles ; in each bundle the inner 
thicker walled tissue is composed of scalariform vessels, 
with a few narrow spiral vessels on each extreme margin • 
surrounding the scalariform tissue is the thinner walled 
sieve tissue, and around this afi^ain is a layer of cells, which 
may be called the bundle sheath ; /, I, intercellular spaces 
surrounding the bundles, x 150.— After Sachs. 



112 BOTANY. 

the bundles are curiously isolated from the surrounding 
ground tissues of the stem. 

141. — The bundle of the nearly related Lycopodium com< 
planatum is much more complex in its structure (Fig. 101). 
Here there are four parallel plates of tracheary tissue, each 
having a structure like the single plate of the bundle of 
8elagi7iella inmquifolia. Between the tracheary plates there 
is in each case a row of sieve tubes imbedded in a lignified 
tissue composed of elongated cells (sclerenchyma, or fibrous 




Fig. 101.— Cross-section of the stem of Lycopodium complanatum. The flbro-vas« 
cular bundle is composed of four plates of tracht ary tissue (darker in the figure), 
between which are masses of lignified tissue composed of elongated cells; each of 
these latter masses encloses a row of sieve tubes (larger and thicker walled in the 
figure) ; the bundle sheath is seen to bound on its iiiner side a thick mass of very thick 
walled fibrous tissue ; exterior to this (toward B) is a layer of chlorophyll-bearing 
parenchyma, bounded by a well-developed epidermis. The small vessels at the ex- 
treme e'dges of the plates of tracheai-y tissue are narrow and spirally marked ; the 
remainder of each plate is composed of scalariform vessels, X 100.— After Sachs. 

tissue?). Around this central fibro-vascular portion there is 
a layer of parenchyma, and outside of this a bundle sheath, 
which is commonly regarded as marking the boundary of 
the bundle ; it is doubtful, however, whether it should be so 
considered, as exterior to it lies a thick mass of fibrous tissue 
which completely envelops all the previously described 
tissues.* 

* Sachs ("Text-Book/* p. 418) retrards the stem of Lycopodium as 
composed of four united bundles and compares tliem to the separate 
bundles of Selaginella. De Bary (" Anatomie," etc, , p. 362), on the 



THE FIBRO- VASCULAR SYSTEM. 



113 



142. — In the fibro-yascular bundle of tlie stem of Indian 
corn {Zea mais) the central portion is composed of tracheary 




Fig. 102.— Transverse section of flhro-vascular bundle of Indian corn (Zea mais). 
a, side of bundle looliing toward tlie circumference of the stem; i, side of bundle look- 
ing toward the centre of the stem ; ?;, Lhin-walled parenchyma of the fundamental 
tissues of the stem; g,g, large pitted vessels; s, spiral vessel; r, rini;:of an annular 
vessel ; I, air-cavity formed by the breaking apart of the surrounding cells ; v, v, 
latticed cells, or soft bast, a form of sieve tissue, x 550.— After Sachs. 

tissue, consisting of pitted, spiral, ringed, and reticulated 
vessels (Fig. 102, g, g, s, r, and the tissue between v — s, g — g) 

otlier hand, considers the cylindrical portion in the centre as but one 
bundle, belonging to what he terms the Radial type. Both agree in con- 
sidering the fibrous tissue outside of the bundle sheatli as not belong- 
ing to the bundles ; but certainly if this is one bundle, there is as good 
reason for including the fibrous cylinder in it as therf^. is in the case of 
tbe bundle of Indian corn. 



114 



BOTANY. 



Lying by the side of the tracheary tissue (on its outer side as 
it is placed in the stem) is a mass of sieve tissue, composed of 
latticed cells {v, v, Fig. 102). Surrounding the whole is a 
thick mass of fibrous tissue composed of elongated, thick- 
walled cells (the shaded ones in the figure). 

143. — The fibro-vascular bundle of the flowering-stalk of 
Acorus calamus bears a close resemblance to that of Indian 
corn. Like that, it has a central tracheary portion (g, Fig. 
103), which has lying exterior to it a mass of sieve tissue {w, 

Fig. 103). On the inner 
side there is a large in- 
tercellular canal, evi* 
dently holding the same 
relation to the other 
tissues that the smaller 
canal does in the bundle 
of Indian corn. The 
exterior of the bundle 
is here also made up of 
a thick mass of fibrous 
tissue. 

144. — In the fibro- 
vascular bundle of the 
adventitious roots of 
Acorus calamus the ar- 
rangement of the tis- 
sues is very different 
from that described 

ary tissue, /an intercellnlar canal ; the periphery Q-KnA/a TTavp fliPrP arp 
of the bundle is composed of thick-walled fibrous •^'J^ve. XltJie Liieie die 

1 issue (figured dark), x i45.-After De Bary. many radially placed 
plates of tracheary tissue {pp, Fig. 104), which alternate 
with thick masses of sieve tissue {ph, Fig. 104). Between 
these alternating tissues, and within the circle formed by 
them, there is a mass of parenchymatous tissue. The 
whole bundle is separated from the large-celled parenchyma 
of the root by a well-marked bundle sheath {s. Fig. 104) ; 
the latter is bounded interiorly by a layer of active thin- 
walled cells — the pericambium — from which new roots 
originate. In the ^Ider root, the central cell mass (which, 




FJg. 103.— Transverse section of a portion of 
the general peduncle of Aconis calamus, g, epi- 
dermis ; &, small fibro-vascular bundle ; in the 
large bundle zv is the sieve tissue, g the trache 



THE FIBBO-YASGULAB 8T8TEM. 



115 



as described above, is in younger specimens composed 
of parenchyma) is transformed into sclerenchyma (Fig. 

105). 

145^ The fibro-vascular bundles of Ricinus com?nunis 

have an arrangement in the stem, and a general structure 
somewhat similar to those of Equisetum palustre, described 
above. The limits of the bundles are so poorly marked that 




Fig. 104.— Transverse section of the flbro-vaseular bundle of the root of Acorus 
calarrms. s, bundle-sheath (also called endodermis), with parenchyma outside and a 
single layer of pericambium-cells inside; /;/>. plates of radially-placd tracheary 
tissue ; ph^ bundles of sieve tissue ; -pp. narrow peripheral (and first formed) ves- 
sels ; g, large and still young vessel.— After ISachs. 



in places it is impossible to tell whether the tissues belong 
to them or to the surrounding ground tissues. 

The inner portion of the bundle {g, g, t, t, Fig. 106, and s 
to t, Fig. 107) is made up of tracheary tissue of several varieties; 
on the inner edge of this tracheary portion lie several spiral ves- 
sels (s, s, Fig. 107) ; next to these, on their outer side, are sca- 
lariform and pitted vessels {t, t, g, g, Fig. 106, I, t, t', Fig. 
107), intermingled with elongated cells, whose walls are pitted 



116 



BOTANY. 



{h, h', h", li", Fig. 107). The last-named areelearly related 
to the vessels which surround them, and from which they 
differ only in their less diameter, and in having imperforate 
horizontal or oljlique septa. They are doubtless properly 
classed with the Tracheides (see p. 84). On the outer side of 
the trachcary portion just described lies a mass of narrow, 
somewhat elongated, thin-walled cells, wdiich constitute a 
true meristem tissue, to which the name of Cambium* has 
been given {c, c, Figs. lOG and 107). Next to the cambium 




Fig. 105.— A very thin cross-section of the radial fibro-va?cular bundle of an old 
adventitious root of Acorvs calamus, g, the radial plates of tracheary tissue ; w, the 
sieve tissue alternating with the plates of tracheary tissue ; 5, the bundle-sheath ; 
the tissue in the centre of the bundle is sclerenchyma. x 145.— After De Bary. 

lie, in order, sieve tissue and parenchyma; these do not occupy 
separate zones, but are more or less intermingled, forming 
a mass sometimes called the Soft Bast {y, y, y, Fig. 106, and 
p, Fig. 107). The sieve tissue includes sieve tubes and 
cambiform or latticed cells. In the extreme outer border of 
the bundle is amass of fibrous tissue {h, h, Figs. 106 and 107). 
The layer of starch-bearing cells just outside of the last- 
named tissue is the so-called bundle sheath. 

* Cambium, a low Latin word, meaning a liquid which becomes 
glutinous. The term was introduced when the real structure of the 
part to which it was applied was not understood. 



THE FIB BO- VASCULAR SYSTEM. 



117 



146. — The bundle of the adyentitions root of Ranunculus 
repens is very diiferent from the one just described. It may 
be briefly described as composed of a mass of tracheary tis- 




■pig. 106.— Transverse section of hypocotyledonary portion of stem of Eicinus corn- 
munis, r, 7% parenchyma of the primdry cortex ; m, parenchyma of the pith •. b, 
bast fibres ; y, y, soft bast ; c, cambium ; g, g^ larjze pitted vessi'ls ; t, t, smaller pit- 
ted yessels ; cb, continuation of the cambium into the parenchyma lying between the 
bundles— the parenchyma-cells are repeatedly divided by tans^ential walls. Between 
the primary cortex r and the fibrous tissue of the phloem lies a layer, the so-called 
bundle-sheath, filled with compound starch grains. Highly magnified.— After Sachs. 

sue, which is cross-shaped, as seen in transverse section {rj. 
r, ^, Fig. 108), and four masses of sieve tissue, which lie in 
the angles between the projecting portions of the trachear}'' 
tissue. Around the Avhole is a layer of pericambium (p^ 



118 



BOTANY. 



Fig. 108), and exterior to this is tlie bundle sheath {u, Fig, 
108). 

147. — In Gymnosperms and Dicotyledons the fibro-vascu- 
lar bundles of the stems have a structure essentially like that 
of Ricmiis C07mnu7iis, described above. In them it is evi- 
dent at a glance that the bundle is divided into two some- 
what similar portions, an inner and an outer, by the cam- 




Fig. 107.— Longitudinal radial section of the fibro-vascular bundle of the hypocot- 
yledonary stem of Eicinus communis (the transverse section being shown in Fig. 
106). r, parenchyma of the primary cortex ; gs, bundle sheath ; m, jjarenchyma of 
the pith ; b, bast fibres ; p, phloem parenchyma ; c, cambium ; the row of cells be- 
tween c and p is afterward developed into a sieve-tube— this and c constitute the 
soft bast ; ■?, the first-formed narrow spiral vessel ; from s the development of the 
xylem portion of the bundle is toward t ; s\ wide spiral vessel : I, scalariform ves- 
sel ; t, t\ wide pitted vessels ; q, the absorbed septum ; h". h'". tracheides (?) ; A, W, 
forms of cells apparently intermediate between pitted vessels and tracheides. Highly 
magnified.— After Sachs. 

bium zone. Nageli,* who first pointed out these divisions, 
named the inner one the Xylem portion, because from it the 
wood of the stem is formed ; the outer he named the Phloem 
portion, for the reason that it develops into bark.f In 
some cases the similarity between the structure of xylem 



* " Beitrage zur Wissenscliaftlichen Botanik," 1858. 

4* Xylem from ^vlov, wood ; Phloem from Greek ip'koLbi;, bark. 



THE FIB BO- VASCULAR SYSTEM. 



119 



and phloem is so marked that they are said to be composed 
of corresponding tissues, (1) Vascular, (2) Fibrous, and (3) 
Parenchymatous.* The vascular tissues are, on the one 
hand, the tracheary tissue found only in the xylem, and on 
the other, the sieve tissue of the phloem. The fibrous tissue 
of the xylem is the variety with the shorter and harden 




Fig. 108.— Cross-section of the fibro-vascular bundle of an old adventitious root of 
Eanunculus repens. g, g, g, the outer margins of the radial plates of tracheary tissue ; 
7", a large central pitted vessel ; x , septum in pitted vessel, with its central portion 
absorbed ; p, pericambium ; u, bundle sheath ; between the four projecting parts of 
the tracheary portion of the bundle, and just within the pericambium, lies the sieve 
tissue. X 145.— After De Bary. 

fibres, known as wood fibres ; that of the phloem is com- 
posed of the longer and tougher bast fibres. The paren- 
qhyma of the two portions is much alike. 

* Attention should be called here to tlie fact that in a good many 
orders of Phanerogams the laticiferous vessels are constituent parts of 
the fibro-vascular bundles. Thus in Cichoriaceae, Campanulaceae, 
Papaveraceae, Asclepiadacese, Apocynaceae, and Acerinese they occur in 
the phloem; in Papayaceae and Aroideae they occur in the xylem. 



120 BOTANY. 

148. — Nageli extended tliis classification of the tissues to 
the tibro-vasciilar bundles of Monocotyledons, and subse- 
quently it has been still further extended so as to include all 
kinds of fibro-vascular bundles. In every case the tracheary 
portion is the essential, or most constant, characteristic of 
the xylem, as the sieve tissue is of the phloem. 

These terms are valuable when used in reference to the 
fibro-vascular bundles of the stems of Phanerogams ; they 
may also be valuable, if properly used and understood, when 
applied to other forms of the fibro-vascular bundle. Tho 
xylem portions of the stem bundles of different plants 
among the Phanerogams are homologous parts of the tissue 
systems — the bundles ; but when the term xylem is applied 
to certain parts of two dissimilar bundles — e.g., of Ricinus 
(Fig. 106) and Lycopodium (Fig. 101) — no homology of parts 
should be understood. The tissues themselves, in some 
cases of dissimilar bundles, may be homologous, but they are 
homologous tissues, and not homologous paints of a system 
of tissues.* When, therefore, these terms are used in the 
present work, it must be borne in mind that they do not 
necessarily convey the idea of homology of parts. 

149. — De Bary's f recent structural classification of fibro- 
vascular bundles is useful in designating their general plan. 
He includes all forms under three kinds, viz., (1) the Col- 
lateral bundle, which has one mass of xylem by the side of 
a single mass of phloem ; this is the form of all bundles of 
the stems of Equisetum, and of the stems and leaves of Pha- 
nerogams X (Figs. 99, 102, 103, 106, 107) ; (2) the Concentric 



* This point, which is an important one, may be made clearer by a i 
illustration from zoolopry. The nervous tissue of one animal is the 
homologue of that found in any other, but the nervous system of one 
may or may not be the homologue of the other. The nervous system 
of the bee, for example, is not the homologue, but the analogue, of 
that of the ox ; it is, however, the homologue of the nervous system 
of the lobster. The brain of the ox and the brain of the bee are not 
homologues as parts of a system, but they are homologues as tissues. 

.-\ " Vergleichende Anatomie," etc., p. 331, et seq. 

r t In the Cucurbitaceae and some other orders there is a mass of sieve 
tissue on the inner side of the xylem, so that the latter is between two 



THE FIBRO-VASCULAR SYSTEM. 131 

bundle, wliicli lias its tissues arranged concentrically aronnd 
one another ; this is the bundle of the stems and leaves of 
ferns (with a few exceptions), Selaginellse, and a few excep- 
tional cases in Phanerogams (Figs. 96, 97, 98, 100) ; (3) the 
Eadial bundle, which has its tissues arranged radially about 
its axis ; such a bundle occurs in the stems of Lycopodiimi, 
and it is the primary bundle of the roots of most Pterido- 
phytes and Phanerogams (Figs. 101, 104, 105, 108). 

150. — The development of the fibro-vascular bundle takes 
place in this wise: in the previously uniform Primary Meris- 
tem there arises an elongated mass of cells, constituting the 
Procambium of the bundle ; as it grows older the cells, 
which were at first alike, become changed into the vessels, 
fibres, and other elements of the bundle tissues. In the 
fibro-vascular bundle of the stems and leaves of Gymno- 
sperms and Dicotyledons this change begins on the two sides 
of the bundle — i.e., on the outer edge of the phloem and 
the inner edge of the xylem ; from these points the change 
into permanent tissue advances from both sides toward the 
centre of the bundle. In some cases {e.g., in the leaves) 
all of the procambium is changed into permanent tissue, 
forming what is termed the closed bundle; in other cases 
there is left between the phloem and xylem a narrow zone 
of the procambium (now called the Cambium), forming 
what is known as the open bundle. 

151. — In the stem and leaf bundles of Monocotyledons 
the development of procambium into permanent tissue is 
essentially as in Dicotyledons and G-ymnosperms, with this 
difference, that here they all become closed. In Pteridophytes 
and the roots of Phanerogams the development, while agree- 
ing in general with the foregoing, is quite different as to de- 
tails; all are closed, unless those in the roots of Dicotyledons 
and Gymnosperms should be shown to be exceptions. 

152. — The fibro-vascular bundles of leaves and the re- 
productive organs are quite generally reduced by the absence 

so-called phloem portions. Such bundles are considered by De Bary to 
be variations of the collateral form, and he designates them as bi-col- 
lateral bundles. 



122 



BOTANY. 



of one or more tissues; this reduction may be so great as to 
leave bat a single tissue, which in many cases is composed of 
only a few spiral vessels or tracheides (Fig. 109). In other 
cases, instead of spiral vessels the bundle may consist of a few 
fibres of bast ; or of elongated, thin- walled cells, which are 
doubtless to be regarded as meristem-cells which failed to 

fully change into one of the or- 
dinary joermanent tissues ; this 
last is a very common accom- 
paniment of reduced bundles. 

{a) In the study of the structure 
of fibro-vascular bundles much care 
is required in the preparation of the 
specimens. The thin transverse sec- 
tions are obtained by ordinary pro- 
cesses with no great difficulty, but 
such is not the case with the lon- 
gitudinal sections ; they must not 
only be extremely thin, but must run 
parallel with the cells and fibres, 
and moreover, must be sufficiently 
large to show all, or a considerable 
part, of the bundle. It is necessary 
also to have several longitudinal 
sections, and to know the exact posi- 
tion of each one when compared 
with the transverse section. 

(h) The most satisfactory results 
can be obtained only by the use of 
some mechanical section-cutter.* In 
most cases the sections are made 
more easily after soaking the stems, 
roots or leaves used in alcohol. 

(c) In many cases it is profitable 
to macerate some of the longitudi- 
nal sectiouiS in nitric acid and potassi- 
um chlorate (Schulze's maceration), 
so as to permit of an isolation of the fibres, cells, and vessels. 

{d) Good specimens for study may be obtained from any of the 
higher plants, but the examination will be most profitable if the order 

* For the various contrivances used for cutting sections see the com- 
mon books on microscopy, also American Naturalist, 1874, p. 59 ; 
American Quarterly Microscopical Journal, 1%'^iQ, p. 131, and several 
articles in Qr. Jour. Mic. Science, 1870, 1874, 1875, 1877. 




Fig. 109.— Terminal ramifications of 
the reduced fibro-vascular bundles of 
the leaf of Psoralea bituminosa; the 
ends X , X , are cut off" in making the 
preparation, the others are the actual 
termini ; the bundles are seen to be 
composed of spiral tracheides, and 
spiral vessels resulting from their fu- 
sion ; around the bundles are seen the 
cells of the chlorophyll-bearing paren- 
chyma. X 225.— After De Bary. 



TEE FUNDAMENTAL SYSTEM. 123 

4fl the followincf list of examples is observed : (1) the rhizomes and 
roots of ferns; (3) stems of Selaginella and Lycopodium ; (3) stems of 
Monocotyledons ; (4) stems of Equisetum ; (5) young stems of Gymno- 
sperms and Dicotyledons ; (6) roots of Phanerogams ; (7) reduced 
bundles of leaves. 

{e) The discussion of the disposition of the bundles in the stem, and 
their relation to the leaf bundles, together with the development and 
structure of secondary bundles, belongs properly to the special anatomy 
of the Phanerogams, (See Chapter XX.) 

§ IV. The FuNDAMEjq^TAL System, or the System of 
Geouxd Tissues. 

153.— These terms refer to the mass of yarious tissues 
lying within the epidermis, and not included in the fibro- 
vascular bundles, when they are present. In passing down 
through the lower plants this inner mass becomes more and 
more simple, until it is composed of but one homogeneous 
tissue, when the term system can no longer be profitably 
applied to it ; in passing to the higher plants, on the other 
hand, there is in this portion of their structure an increasing 
complexity, which comes at last to more than equal that of 
either the epidermal or fibro-vascular systems. 

154.— In its fullest development, the fundamental system 
may contain parenchyma of various forms, collenchyma, 
sclerenchyma, laticiferous tissue, and possibly also fibrous 
tissue.* Their arrangement, within certain limits, presents 
a considerable degree of similarity in nearly related groups 
of plants, but this is by no means as marked as in the case of 
the fibro-vascular system. 

* It is a question whether fibrous tissue occurs in the fundamental 
system ; there are some cases {e.g., in Ferns, Lycopodiacese, etc.) 
which appear to show that it does, but possibly they admit of other in- 
terpretation. It should be mentioned here that many eminent botanists 
(notably Schwendener, Russow, Falconberg, and De Bary) hold that all 
fibrous tissue belongs to the fundamental system, and as a consequence, 
that it in no case is a proper constituent of the fibro-vascular bundle. 
This is, however, nothing more than making a typical form of bundle 
(composed of tracheary and sieve tissues), and then insisting that all tis- 
eues not found in the type are extra-fascicular, a course which cannot 
be followed in this book. 



124 



BOTANY 






(1.) Parencliyma is tlio most constant of the fundamental 
tissues ; it mnkos up tlie whole of tlie interior plant-body in 
tliose cases where there has been no differentiation into more 
than one tissue, and from here, it is present in varying 
amount in nearly all (if not all) cases up to and including 
the highest plants. In stems of Monocot3dedons it makes up 
the mass of tissue lying between the scattered bundles, and 
in stems of Gymnosperms and Dicotyledons it constitutes 
the pith and portions of the bark. 

(2.) Collenchyma, when 23resent, as it frequently is in the 

stems and leaves of Dicotyle- 
dons, is always either in con- 
tact with or near to the epi- 
dermis. 

(3.) Sclerenchyma is com- 
mon beneath the epidermis 
of the stems and leaves of Bry- 
ophytes, Pteridophytes, and 
Phanerogams. It appears to 
replace collenchyma in parts 
having greater firmness than 
that given by the latter. Some 
forms of sclerenchyma are 
scarcely to be distinguished 
from fibrous tissue — e.g., in 
the hypoderma of pine leaves 
(Fig. 110, g, i'). It may be 
that the supposed cases of fibrous tissue among the funda- 
mental tissues will turn out to be sclerenchyma instead. 

(4.) Laticiferous tissue may occur, apparently, in any por- 
tion of the fundamental system of Phanerogamous plants. 

155.— It is thus seen that in general the tissues of the 
fundamental system are so disposed that the periphery is 
harder and firmer than the usually soft interior, although 
there are many exceptions. This general structure has given 
rise to the term Hypoderma for those portions of the funda- 
mental system which lie immediately beneath, or near to the 
epidermis. Hypoderma is not a distinctly limited portion — 
in fac*", it is often difficult to say how far it does extend; 




Fig. 110.— Margin of \e&i of Pinus pin- 
aster, transverse section ; c, cuticular- 
ized layer of outer wall of epidernais ; i, 
inner non-cuticularized layer ; c', thick- 
ened outer wall of marginal cell ; g, i', 
hypoderma of elongated sclerenchyma ; 
p, chlorophyll-bearing parenchyma ; pr, 
contracted protoplasmic contents, x 
800.— After Sachs. 



TEE FUNDAMENTAL SYSTEM. 



125 



however, it usually includes several, or even many, layers of 
oells, or the whole of each of the tissue-masses {e.g., coUen- 
chyma, sclerenchyma, etc.) which immediately underlie the 
epidermis (Fig. 110, g, i). 

The remaining portion of the fundamental system, inside 
of the hypoderma, is designated by Sachs as the Intermediate 
tissue. The term is of but little value in many of the higher 
plants, where more particular names may be applied ; but in 
some Monocotyledons, most Pteridophytes, and in Bryo- 
phytes it is very 
serviceable. e ^i 

156. — Cork. 
Within the zone 
which the hypo- 
derma includes 
there frequently 
takes place a pe- 
culiar develop- 
ment of the 
young parenchy- 
ma, giving rise 
to layers of dead 
cells, whose cav- 
ities are filled 
with air only. 
The walls in 
some cases {e.g., 
the cork-oak) are 
thin and weak, 
while in others {e.g., the beech) they are much thickened, 
and in all cases they are nearly impermeable to water. True 
cork is destitute of intercellular spaces, its cells being of 
regular shape (generally cuboidal) and fitted closely to each 
other (Fig. 111). 

157. — Cork substance is formed by the repeated subdivis- 
ion of the cells of a meristem layer of the fundamental tissue 
(Fig. Ill) ; these continue to grow and divide by parti- 
/Eions parallel to the epidermis, forming layers of cork with 
its cells disposed in radial rows (Fig. Ill, h). Shortly after 




Fig. 111.— Transverse section of one-year old stem of Ai- 
lanthus glandulosus. e, epidermis ; k, cork-cells ; r, inner 
green cells, the phelloderma ; between k and r a layer of 
cells filled with protoplasm, called the phellogen or cork 
cambium, x 350.— After Prantl. 



126 



BOTANY. 



their formation tlie cork-cells lose their protoplasmic con- 
tents, while beneath them new cells are constantly being cut 
off from the cells of the generating layer ; in this way the 
mass of dead cork tissue is formed and pushed out from its 
living base. 

158. — The generating tissue is called the Phellogen,* or 
Cork-cambium ; it occurs not only in the hypoderma, but in 
any other part of the fundamental system, and, as will be 
shown hereafter, in the secondary fibro-vascular bundles. 
When a living portion of a plant is injured, as by cutting, 
the uninjured parenchyma-cells beneath the wound often 
change into a layer of phellogen, from which a protecting 

mass of cork is then 
developed. 

159. — Lenticels 
are in many cases the 
result of a restricted 
corky growth just be- 
neath a stoma. Phel- 
logen consisting of a 
few cells of the hjrpo- 
derma, is formed im- 
section mediately below a 

)ve ; 35, a;, 'cell 8 which are beginning the process of gf^yy^j, /'TTifr 119 />•^ • 
Itiplication by fission, constituting the phellogen ■M>'Jiii<A ^-^ ^g« -I--L/&, Xj , 
the future lenticel. X 375.— After De Bary. ]jy ^q ffrowtll of COrk 

from this phellogen the epidermis is pushed out and finally 
ruptured, exposing the roundish or elongated mass of corkf 
(Fig. 113). Lenticels are of frequent occurrence on the young 
branches of birch, beech, cherry, elder, lilac, etc. , and may be 
distinguished by the naked eye as slightly elevated roughish. 
spots, usually of a different color from the epidermis. 

(rt) The examination of the tissues of the fundamental system may 
in general be made with, considerable ease, by making transverse,tan- 
gential and radial sections. 




Fig. 112.— Transverse section of a portion of the 
Intemode of a young twig of Betula alba, c, cuticle, 
somewhat separated from the epidermis ; e, e, epider^ 
mis ; a, cavity under the stoma seen in cross 
above 
mu 
of the future lenticel. 



* From the Greek <pel?.o^, cork. 

f It appears quite certain that not all lenticels develop from the 
hypoderma beneath stomata ; phellogen forms beneath the epider- 
mis at other points, and gives rise to lenticels in a way essentially as 
in the other cases. 



THE FUNDAMENTAL SYSTEM. 



127 



(&) Ordinary herbaceous Dicotyledons furnish the best examples of 
fully developed fundamental tissues ; they can be most easily exam- 
ined after soaking for some time in alcohol. 

(c) Examples of thin- walled cork are, of course, best obtained from 




Fig. 113.— Transverse section through a lenticel of Betula alba, e, e, epidermis ; s, 
old stoma ; under this is a mass of cork which develops from the phellogen layer 
lying next to the ordinary parenchyma (figured darker) ; the great multiplicatioH of 
cork-cells has pushed out the epidermis. X 280.— After De Bary. 

the ordinary commercial article ; the thick-vralled form may be obtained 
from the bark of the beech, willow, prickly ash {Xanthoxylum Amer- 
icanum), Viburnum opulus, etc. Its development may be observed by 
making successive sections of the shoots at different heights. 



CHAPTER VIII. 

IlSrTERCELLULAE SPACES AND SECRETION RES- 
ERVOIRS. 

160. — In addition to the cavities and passages which are 
formed in the plant from cells and their modifications, there 
are many important ones which are intercellular, and which 
at no time were composed of cells. In some cases they so 
closely resemble the cavities derived from cells that it is with 
the greatest difficulty that their real nature can be made out. 
In their simplest form they are the small irregular spaces 
which appear during the rapid growth of parenchyma-cells 
(Fig. 51, p. 67) ; from these to the large regular canals 
which are common in many water plants there are all inter- 
mediate gradations. 

161. — In leaves, especially in the parenchyma of the under 
portion, there are usually many large irregular spaces be- 
tween the cells ; they are in communication with the exter- 
nal air through the stomata, and contain only air and watery 
vapor. The petioles and stems of many aquatic plants con- 
tain exceedingly large air- conducting intercellular canals, 
which occupy even more space than the surrounding tissues 
(Fig. 9, page 20). In the "Water-lilies {Nymphceacece) and 
Water-plantains {Alismacece) they are so large as to be read- 
ily seen by the naked eye, and in the Naiads {Naiadacem) 
they are almost equally large (Fig. 114). In the fibro-vascu- 
lar bundles of Equisetum, and of many Monocotyledons and 
some Dicotyledons, there are intercellular canals, sometimes 
of very considerable diameter (Figs. 99, 102, 103). Lastly, 
in the medullary parenchyma (pith) of many plants there is 
a large central cavity (although formed in part by the rup- 
ture of some cell-walls), which must be considered as inter- 



INTERCELLULAR SPACES. 



129 



cellular ; of this nature are the cavities in many hollow stems 
—e.g., in many Umbelliferae and Gramineae. 

162. — There are in many plants intercellular spaces and 
canals which are made the receptacles for special secretions, 
and to which the 
name of Secretion 
Reservoirs may be 
applied. They are 
surrounded ( at 
first, afc least) by 
secreting cells, 
which furnish the 
oil, gum, resin, and 
other substances 
(seep. 62) found in 
the reservoirs. 
Their structure 
and mode of de- 
velopment may be 
illustrated by the 
gum-canals of the 
Ivy {Hedera helix). 
Each at first con- 
sists of a long col- 
umn developed in 
the phloem, and 
composed of four 
or five rows of thin- 
walled cella arrang- 
ed radially about a 
common axis. The 
cells soon separate 
from each other in 
the axis of the col- 
umn, and thus 
fo'-m a small canal 
(Fig. 115, A), which is afterward increased in diameter by 
the formation of radial partitions, and the tang^ential growth 
of the surrounding: cells (Fig. 115, E). The surrounding 




Fig. 114.— Part of the transverse eectioti throueh the 
internode of the stem of Potamoqeton pectinatus, show- 
insT the large intercellular spaces between the central 
fibro-vascular bundle and the circumference of the stem ; 
f, e, epidermis; a, a small bundle, consisting of surround- 
ing fibrons tissne and a v^ry small central mass of sieve 
tissue; b, b, b. small bundles containing only fibrous ti"*- 
sue; u, bundle sheath of principal bundlR in the axis of 
the stem, within which is a mass of sieve tissue snrround- 
ing the intercellular canal, g. X 80.— After De Bary. 



130 



BOTANY. 



cells secrete a peculiar sap or gum, which passes into and 
tills up the canal. 

In the Coniferae the turpentine canals have essentially the 
same structure. They are found in the bark, wood and pith ; 
they occasionally unite with one another, or change their 
direction- through some of the medullary rays, the cells of 
which have apparently become transformed into resin-secret- 
ing tissue. 

163. — Allied to the foregoing, although formed in a 
slightly different way, are the small secretion reservoirs of 
many plants, and in which oils, resins, gums, and other 





Fig. 115.— Transverse sections of young stem of Ivy {Eedera helix). A, young in- 
tercellular gum canal, surrounded by four cells ; c, cambium ; ivb, soft bast ; E, 
fully developed canal, g ; b, bast ; rp, cortical parenchyma, x 800.— After Sachs, 



odorous substances are collected. The fragrance of many 
fruits — e.g., oranges and lemons — is due to the oils and other 
matters contained in such receptacles. In Dictamnus frax- 
inella these are developed as follows : two mother-cells {p, p, 
Fig. 116) appear in the hypoderma and divide by several 
partitions, forming a mass of thin-walled secreting cells 
(Fig. 116, B) ; these, by a degeneration of their walls, fuse 
into a common cavity filled with oil and watery matter (Fig. 
116, C). It appears that the outer layer of secreting cells 
{('-, c) is developed from the epidermis (Fig. 116, A, d, c); 
hence this is partly an epidermal structure. 

Of like nature are the reservoirs in the ^' glandular hairs " 
of the same plant ; in fact, the two structures are apparently 



SECRETION RESERVOIRS. 



131 



but slightly different developments of the same organ (Fig. 
117). 

{a) The smaller and more irregular intercellular spaces may be 
studied in the fundamental tissue of the stem of Indian corn, in the 
parenchyma of most leaves, and the stems of Juncus. 




Fis. 116. 



Fig. 116. — Internal glands of the leaf of Dictamnus fraxinella. A and B, early 
etages of development; C, mature gland ; d, epidermis ; c, p, mother-cells of the se- 
creting cells ; 0, drop of ethereal oil.— After Ranter. 

Fig. 117.— Glandular hair of the inflorescence of Dictamnus fraxinella ; A and B, 
earliest stages, showing the origin to be similar to that of the internal glands ; C, fully 
developed hair ; the part h is the true hair, while all below it, including the oil cav- 
ity, is to be regarded as an outgrowth of the sub-epidermal cells. X about 220.— After 
Ranter. 



(&) Thin cross-sections of the stems and petioles of Nymphma, 
Nuphai\ Nelumtium, Sagittaria, Potamogeton, and many other water 
plants, afford excellent specimens for the study of intercellular c inals. 



132 



BOTANY, 



Tlie relation of tho intcrcollular spaces of the leaves to the canals of 
the petioles may be studied l)y carefully made longitudinal sections. 

(c) The resin canals of Silphium laciniatum and ^S". perfoliatura, and 
the turpentine canals of Coniferae, furnish excellent examples of the 
larger secretion reservoirs, while the smaller ones may be studied in 
the cavities in the rind of the orange and lemon, the leaves of Dictmu' 
WIS, Xanthox^illum, Rue (Buta), Hypericum, and many Labiatae. 



CHAPTER IX. 

THE PLANT-BODY. 

§ I. Gen"eealized Foems. 

164. — The cells, tissues, and tissue systems described in 
the preceding pages are yariously arranged in the different 
groups of the vegetable kingdom to form the plant-body. 
The simplest plants are single cells or undifferentiated 
masses of cells ; in those next higher the cells are aggre- 
gated into simple tissues, while still above these the tissues 
are grouped into tissue systems. With this internal differ- 
entiation there is a corresponding differentiation of the ex- 
ternal plant-body. The lower plants are not only simpler as 
to their internal structure, but they are so as to their exter- 
nal form as well. The higher plants are as much more 
complex than the lower ones as to their external parts as 
they are in regard to their tissues and tissue systems. 

165. — In the lowest groups of plants the simple plant- 
body has no members ; the single-or few-celled alga has no 
parts like root, stem, or leaf ; it is a unit as to its external 
form. In the higher groups, on the contrary, the plant- 
body is composed of several to many less or more distinct 
members. In those plants in which they first appear, the 
members are not clearly or certainly to be distinguished from 
the general plant-body ; but in the higher groups they be- 
come distinctly set off, and are eventually differentiated into 
a multitude of structural and functional forms. 

166. — As will be seen in the future chapters, every plant, 
in its earliest (embryonic) stages, is simple and memberless ^ 
and every member of any of the higher plants is at first indis- 
tinguishable from the rest of the plant-body ; it is only in 



134 BOTANY. 

tlie later growth of any member that it becomes distinct ; in 
other words, every member is a modification of, and develop- 
ment from, the general plant-body. Likewise, where equiva- 
lent members have a different jDarticular form or function, 
it is only in the later stages of growth that the differences 
appear. All equivalent members are alike in their earlier 
stages, whether, for example, they eventually become broad 
green surfaces (foliage leaves), bracts, scales, floral enyelopes, 
or the essential organs of the flower. 

167. — These facts make it necessary to have some general 
terms for the parts of the plant-body, which are applicable 
to them in all their forms. We must have, for example, a 
term so generalized as to include foliage leaves, bracts, scales, 
floral envelopes, and all the other forms of the so-called leaf- 
series. So, too, there is need of a term to include stems, 
bulbs, bud, and flower axes, root-stocks, corms, tubers, and 
the other forms of the so-called stem-series. 

168. — By a careful study of the members of the more 
perfect plants we find that they may be reduced to four 
general forms, viz., (1) Caiilome, which includes the stem 
and the many other members which are found to be its 
equivalent ; (2) Pliyllome, including the leaf and its equiva- 
lents ; (3) Trichome, which includes all outgrowths or ap- 
pendages of the surface of the plant, as hairs, bristles, root- 
hairs, etc. ; (4) the Root, which includes, besides ordinary 
subterranean roots, those of epij)hytes, parasites, etc. 

169. — As indicated above, in the lower plants the differ- 
entiation into members is not so marked as in the higher, 
and in passing downward in the vegetable kingdom groups 
are reached in which it is inappreciable, and finally in which 
it is entirely wanting ; such an undifferentiated plant-body 
is called a Thallome, and may properly be regarded as the 
original form, or prototype. 

170. — Thallome.* The simplest thallome is the single 
cell ; this, though generally rounded, is, in some cases 
{Botrydium, Caulerpa, etc.), irregularly extended into 
branch-like or leaf -like portions, which must not be mistaken 

* From the Greek ^a7Jk6'i^ a. young shoot, branch, or frond. 






I 



GENERALIZED FORMS. 135 

for members coordinate with those mentioned above, as they 
are only parts of a unit, instead of members of a body ; they 
may be regarded as, to a certain extent, f oreshadowings or 
anticipations of the members of the higher plants. Plants 
composed of rows of cells or cell surfaces frequently show 
no indication whatever of a division into members ; but, in 
some cases, there is a little differentiation, which, though 
not carried far enough to give rise to members, is the same 
in kind. In the larger algae there is sometimes so much of 
a differentiation that it becomes difficult to say why certain 
parts ought not to be called members. Caulome and phyl- 
lome, at least, are strongly hinted at in the Fucaceae, and 
in this group, although the term thallome is applied to the 
plant-body, it must be admitted as not fully applicable. 
Structures of this kind are instructive, as showing that the 
pa.ssage from the thallome plant-body to that in which 
members are differentiated is by no means an abrupt or 
sudden one. 

171.— Mutual Relations of Thallome, Caulome, and 
Phyllome. The caulome is the phyllome-bearing axis of the 
plant, and phyllomes are the members developed upon the 
caulome. The two have a reciprocal relation, and in no 
case is the one present without the other. The definition of 
the one involves that of the other. Both are derived 
directly from the thallome, and that differentiation which 
gives rise to one necessarily produces the other. The differ- 
entiation of thallome into caulome and phyllome is simply 
a lobing and contraction of the marginal portions into sepa- 
rable phyllomes, and a rounding and contraction of the 
central or axial portion into a caulome. 

172. — Caulome.* By this general name we designate 
all axial members of the plant. In the more obvious cases 
the caulome is the axis which bears leaves (foliage), and in 
this form it constitutes (1) the Stem; branches are only stems 
which originate laterally upon other stems. 

The other caulome forms are : 

(2.) Runner Sf which are bract-bearing, slender, weak, and 
trailing. 

* From the Greek /cavXoS, stem. 



13G BOTANY. 

(3.) Root-stocks y which are bract or scale-bearing, usually 
weak, and subterranean. 

(4.) Tillers, which are bract or scale-bearing, short and 
thickened, and sul)terranean. 

(5.) Corms, which are leaf -bearing, short and thickened, 
and subterranean. 

(6. ) Bulh-axes, Avliich are leaf -bearing, short and conical, 
and subterranean. 

(7.) Floiver-axeSy^\\\c\\ are bract, perianth, stamen, and 
pistil-bearing, short, and usually conical and aerial. 

(8.) Tendrils, which are degraded, slender, aerial cau- 
lomes, nearly destitute of phyllomes. 

(9.) Thorns, which are degraded, thick, conical, aerial 
caulomes, nearly destitute of phyllomes. 

173. — Phyllome.* The phyllome is always a lateral 
member upon a caulome. It is usually a flat expansion and 
extension of some of the tissues of the caulome. Its most 
common form is (1) the Leaf (foliage), which is usually large, 
broad, and mainly made up of chlorophyll-bearing paren- 
chyma. 

The other phyllome forms are : 

(2.) Bracts, which are smaller than leaves, generally green. 

(3.) Scales, which are usually smaller than leaves, wanting 
in chlorophyll-bearing parenchyma, and with generally a 
firm texture. 

(4.) Floral envelopes, which are variously modified, but 
generally wanting in chlorophyll-bearing parenchyma, and 
with generally a more delicate texture. 

(5.) Stamens, in which a portion of the parenchyma de- 
velops male reproductive cells (pollen). 

(6.) Carpels, bearing or enclosing female reproductive 
organs (ovules). 

(7. ) Tendrils and Spines, which are reduced or degraded 
forms, composed of the modified fibro-vascular bundles, and 
a very little parenchyma ; in the first the structures are weak 
and pliable, in the latter stout and rigid. 

The altogether special modifications of the phyllome, as in 
pitchers and cups, will be noticed hereafter. 

^ From the Greek <pv'k\ov, leaf. 



GENERALIZED FORMS. 137 

174. — Trichome.* The tricliome is a surface appendage 
consisting of one or more cells usually arranged in a row or 
a column, sometimes in a mass. Its most common forms are 
met with in (1) the Hairs of many plants. (See page 95.) 

The other trichome forms are : 

(2.) Bristles, each consisting of a single pointed cell or 
a row of cells, whose walls are much thickened and hardened. 

(3.) Prickles, like the last, but stouter, and usually com- 
posed of a mass of cells below. 

(4.) Scales, in which the terminal cell gives rise by fission 
to a flat scale, which soon becomes dry. 

(5.) Glands, which are generally short, bearing one or 
more secreting cells. 

(6.) Root-hairs, which are long, thin, single-celled (in 
mosses a row of cells), and subterranean. 

(7.) Sporangia of Pteridophytes, some of whose interior 
cells develop into reproductive cells (spores). 

(8.) Ovules of Phanerogams, one or more of whose cells 
develop into reproductive cells (embryo sacs).f 

175.— Boot. The root is that portion of the plant-body 
which is clothed at its growing point with a root-cap. In 
ascending through the vegetable kingdom roots are the 
latest of the generalized forms to make their appearance, 
and in the embryo they appear to be formed later than 
caulome and phyllome. They present fewer variations than 
any of the other generalized forms. The ordinary (1) Sub- 
terranean roots of plants are typical. They differ but little 
from one another in all the groups of the Pteridophytes and 
Phanerogams. 

The other root forms are : 

(2.) Aerial roots, which project into the air, and often have 
their epidermis peculiarly thickened, as in the epiphytic 
orchids. 

(3.) Roots of Parasites, which are usually quite short, and 



'>" From the Greek i?p/^, rptxoS, a hair. 

f It is held by some botanists that in some plants the ovule is "the 
terminal portion of the axis," and that in others it is a leaf or part of a. 
leaf. 



138 



BOTANY. 



in some cases provided with sucker-like organs, by means of 
which they come into a more intimate relation to their hosts. 

176.— Particular Relations of Phyllome to Caulome. 
Sachs* has formulated the relations of phyllome to caulome 
in substance as follows : 

(1.) Phyllomes always originate from the Primary Meris- 
tem of the punctum vegetationis ; fully differentiated tissues 
are incapable of producing them. 

(2.) They are always exogenous formations ; that is, they 




Fig. 119. 



Fig. 118. 



Fig. 118.— Diagrams of dichotomous branching. A, normal dichotomy, in which 
each branch is again dichotomously branched ; B, helicoid dichotomy, in which the 
right-hand branch, r, does not develop further, while the left-hand one, I, is in every 
case again branched ; C\ pcorpioid dichotomy, in which the branches are alternately 
farther developed.— After Sachs. 

Fig. 119.— Diagram of botrj'ose monopodia! branching. The numerals indicate the 
"generations." 

develop from outer and not inner tissues, consequently their 
tissues are externally continuous with those of the caulome. 
(3.) They always originate below the growing apex of the 
caulome as lateral outgrowths ; they may appear singly, so 
that no two are situated at the same height on the stem, or 
two or more may grow at once, generally at equal distances 
from one another in the circumference of the caulome. 



* "Text-Book," p. 131. 



GENERALIZED FORMS. 



139 



(4.) They always arise in acropetal* order. 

(5.) They grow more rapidly than the caulome does above 
their insertion. When they are numerous their rapid growth 
gives rise to the accumulation of phyllomes known as a Bud. 

(6.) The phyllomes of any plant are always of a different 
form than the caulomes. 

177.— G-eneral Modes of Branching of Members. There 
are two general modes of the branching of the members o:' 
the plant-body. In the one, the apex of the growing mem 
ber divides into two new growing points, from which branches 
proceed j this is the Bichotomous mode of branching (Fig. 




Pig. 120.— Diagrams of cyrnose monopodial branching. A and 5, scorpioid cymea ; 
C, forked cymose monopodium, the compound or falsely dichotomous cyme (called 
also the dichasium) • Z>, helicoid cyme.— After Sachs. 

118). In the other, the new growing points arise as lateral 
members, while the original apex of the parent stem still 
retains its place and often its growth ; this is the Mono- 
podial mode of branching (Fig. 119). Both modes are sub- 
ject to many modifications, the most important of which are 
briefly indicated in the following table : 

A.— DICHOTOMOUS. .. 
1. Forked dichotomy, in whicli both branches of each bifurcation are 
equally developed (Fig. 118, A). 

* Acroptthl, tending toward the summit ; from the Greek aK-pa. 
ffuiumit, and Treraw, to move toward. 



140 BOTANY. 

2. Sympodial dichotomy, in which one of the branches of each bifur- 
cation develops more tlian the other, 

a. Helicoid aympodial dichotomy , in which the greater development 

is always on one side (Fig. 118, B). 

b. Scorpioid sympodial dichotomy, in which the greater develop- 

ment is alternately on one side and the other (Fig. 118, G). 

B.— MONOPODIAL. 

1. Botryose monopodium, in which, as a rule, the axis continues to 
grow, and retains its ascendency over its lateral branches (Fig, 119). 

2. Cymose m,oriopodium, in which the axis soon ceases to grow, and is 
overtopped by one or more of its lateral branches. 

a. Forked cymose monopodium, in which the lateral branches are 

all developed (Fig, 120, G). 
h. Sympodial cymose monopodium, in which some of the lateral 
branches are suppressed ; this may be 
h\ Helicoid, when the suppression is all on one side (Fig. 130, 

D); or 
h*\ Scorpioid, when the suppression is alternately on one side 
and the other (Fig. 120, A and B). 

Dichotomous branching takes place in many Thallophytes ; it is 
beautifully seen in the appendages to the perithecia of many Erysipha- 
ceae {e.g., lilac-blight, cherry-blight, etc.) It occurs also in the roots, 
stems, and leaves of many Pteridophytes, and the leaves and other 
phyllome structures of some Phanerogams. 

Monopodial branching is, on the other hand, the general rule for all 
members of the plant-body in Phanerogams, and in Pteridophytes, 
Bryopbytes, and Thallophytes very much of the branching is also of 
this kind.* 

§ II. Stems. 

178. — The primary stem of a plant first develops from the 
meristem tissue of the embryo ; its subsequent growth is a 
growth from the meristem of the punctum vegetationis, to- 
gether with an intercalary growth of its newer parts. On 
account of the more rapid growth of its young leaves, it usu- 
ally happens that the stem is terminated by, and appears to 
grow from, a bud ; in fact, it is a common statement that 
stems grow from buds. It will be necessary to examine the 
bud in detail. 

* A full discussion of this subject would occupy more space than can 
be allotted to it in this book, and any attempt to cover the subject in a 
few pages would tend rather to confuse the student than to enlighten 
Lim. For a good account, the student is referred to Sf»chE' "Text-Book 
of Botany," p. 155 ; Hofmeister'g " Allgemeine Morpholcgic> der Ge- 



STEMS. 



141 



179, — The punctum vegetationis (growing point) of a stem 
is generally a conical point ; upon its curved surface a little 
below its apex the rudiments of leaves appear as slight swell- 
ings or papillae ; as the growing point elongates, and the 
rudimentary leaves grow, new ones appear above the pre- 
viously formed ones. By the more rapid growth of the 
leaves than the newer part of the stem, the latter comes to 
be covered with many closely approximated young leaves. 
This is the usual condition of the ends of growing stems in 
summer, hence such an aggre- 
gation of rudimentary leaves 
may be termed a summer 
bud. While in the apex of 
the bud the leaves grow more 
rapidly than the stem, in its 
base the growth of the stem 
is much the most rapid. This 
later stem-growth is an inter- 
calary one, and it results in 
separating the previously ap- 
proximated leaves a consid- 
erable distance from one 
another, forming the inter- 
nodes of the stem. 

180. — Winter buds have 
essentially the same struc- 
ture, and the same mode of 

formation. In these, how- pig. 121. .Extremity of a branch of the 

ever, most of the phvUome Horse-chestnut (^^m/z^s^wocastonwm); 

/ . "^ a large terminal bud with two smaller lat- 

rudiments develop mto more eral buds ; a, a, «, scars of fallen leaves. 

, , , , -^ , , . , Natural size.— After Duchartre. 

or less hardened scales, which 

grow rapidly and overtop the punctum vegetationis. The 
basal growth of the bud ceases, and soon its apical growth 
also, and thus the scaly phyllomes are left in close approxi- 
mation (Fig. 121). Such a bud is but a state of the ter- 
minal portion of the leaf -bearing stem, and not a new for- 
mation or member ; it cannot even be called an organ. 

181, — Upon the return of warm weather in the spring 

wachse," p. 433, and Eicliler's " Bliithendiagramme," page 33 et seq, 
[n each there are many references given to the literature of the subject. 




142 



BOTANY. 



the basal growth of the bud is resumed, and shortly after- 
ward, or simultaneously, the apical growth also. The thick 
scales separate by the slight elongation of the stem, and being 
of no further use to the plant they soon fall off. The inter- 
calary growth of the scale-bearing portion of the stem is gen- 
erally much less than of that which bears leaves, hence the 
first internodes which appear in the spring of the year are 
quite short. The punctum vegetationis of such a winter 
bud, after resuming its activity, goes on developing leaves as 
lateral members exactly as if there had been no interruption 
in its activity. Upon the approach of autumn again the 




Fig. 122. — Longitudinal section of the apex of the stem of a moss (Fontinalis anti- 
pyretica). v, apical cell ; «, outer part of one of the segments cut off from apical 
cell ; «, apical cell of a lateral leaf-bearing shoot arising below a leaf; c, first cell of 
a leaf ; b, b, cells forming cortex. —After Leitgeb. 

same process of bud-formation takes place by the decrease in 
the rapidity of extension, and its final cessation ; this is fol- 
lowed again by the resumption of growth upon the advent of 
spring. Thus the stem exhibits a periodicity in its growth, 
and one of its phases is the so-called winter bud. 

182. — Branches of stems (lateral stems) normally originate 
in the punctum vegetationis . as lateral outgrowths (Fig. 
122, z) ; each develops first into a conical mass, w^hich then 
becomes the punctum vegetationis of a new stem, and upon 
it lateral members arise, as in the case of the principal stem. 
The new stem may elongate at once into a leafy shoot, as 



STEMS, 



143 



takes place in annuals ; on the other hand, it may make but 
little growth in extension, so forming a bud, as is common 
in perennials (Fig. 123). Buds like the last, which are 
apparently sessile upon the parent axis, are said to be lateral, 
although, strictly speaking, they are 
terminal upon yery short stems. 

183. — It most frequently hap- 
pens that new stems arise near to 
certain leaves. The origin of the 
stem may be below the leaf, as in 
many Bryophytes {z, Fig. 122) ; or 
beside it, as in Equisetaceae ; or 
above it in its axil, as in Monocoty- 
fedons and Dicotyledons (Fig. 121), 
and it appears that in each case the 
new stem originates shortly after 
the leaf. 

184. — In Monocotyledons and 
Dicotyledons there are usually as 
many new stems formed as there 
are leaves ; exceptionally there may 
be several new stems (supernumer- 
ary stems or buds) formed in the 
axil of each leaf (Fig. 123.) In 
mosses, ferns, and Conifers, on the 
contrary, there are by no means as 
many new stems as there are leaves. 

185. — Rarely, new stems (adven- 
titious stems or buds) arise from 
the older parts of plants ; thus they 
may arise from petioles and ribs of 
some leaves — e.g., Begonia, Bryo- 
phyllum, etc. ; from the cambium of 
the cut surfaces of stems — e.g., 
elm, willow, etc. ; and sometimes in 
abundance from the fibro-vascular 
bundles of roots — e.g., Populus alba, cherry, sweet potato, 
elvC. Such structures are always endogenous, as in all cases 
tliey spring from some portion of, or near to, the fibro-vas- 
cular bundles, and break through the overlying tissues. 




Fig. 123.— Branch of the Cher- 
ry bearing lateral bads ; W, b\ b', 
buds from which leafy branches 
will develop ; b, b, b, bads from 
which flowers will develop. Nat- 
ural size.— After Duchartre. 



144 BOTANY. 

186. — Frequently the new stems whicli are normally formed 
make but a very little growth, and in perennials become 
covered by the subsequently formed tissues ; they thus become 
the so-called dormant buds. Under favorable conditions they 
may resume their growth long afterward, and they are then 
liable to be mistaken for adventitious stems. Probably very 
many of the supposed cases of adventitious stems upon the 
older stems of Dicotyledons are in reality only the late 
growths of stems which have been dormant for a long time. 

{a) The development of stems may be studied in almost any plant. 
Those which have large winter buds, however, offer some advantages 
to the beginner. Such are the buds of hickory, horse-chestnut, lilac, 
etc. 

(&) Vertical sections should be made of the buds before they resume 
their growth in the spring, and these should be compared with similar 
sections made after some growth has taken place. 

(c) Many of the common annuals with a continued growth — e.g., 
balsam, mallow, etc. — may be profitably studied for making out the 
growth of summer buds. The young skoots of many shrubs — e.g.^ 
elder and lilac — are also excellent for study. 

id) Thin enough longitudinal sections should be made to show the 
punctum vegetationis. The specimens may often be made much more 
instructive by coloring with carmine, or other staining fluids. 

§ III. Of Leaves ix General. 

187. — Every leaf originates in the Primary Meristem of 
the punctum vegetationis. It is at first a small projection 
or papilla, composed of one or more cells, which undergo a 
rapid division, thereby producing the quick early growth 
before mentioned (p. 139). Generally the multiplication of the 
cells is such as to give rise to a surface whose plane cuts the 
stem transversely. In many cases the apex of the leaf soon 
becomes changed into permanent tissue while the base con- 
tinues to grow, indefinitely in grasses and many other 
Monocotyledons, and definitely in most Dicotyledons. In 
other cases the base passes over into permanent tissue, while 
the apical portions keep on growing, as in ferns and some 
pinnate leaves of Dicotyledons. 

188. — Many leaves are raised upon a stalk by a subsequent 
growth between the stem and the base of the leaf ; this leaf- 



H OF LEAVES IN GENERAL. 145 

stalk (petiole) is much extended in the lower leaves Of many 
plants, especially of those which grow in the shade or are 
intermixed with other plants. Structurally the petiole is the 
extension of the fibro-vascular and parenchymatous connec- 
tion between the leaf and the stem ; and it generally forms 
an articulation or joint with the stem at its lower extremity ; 
physiologically it is a support for the leaf, and it is longer or 
shorter just as elongation or want of it places the leaf under 
the best physiological conditions. 

189. — The leaf is, when first formed, destitute of fibro-vas- 
cular bundles, and this is the permanent condition of the leaves 
of Bryophytes, and the leaf -like portions of the Thallophytes. 
In most higher plants, however, portions of the leaf tissue 
early become differentiated into one or more fibro-vascular 
bundles, which pass downward into the stem and unite 
with the older bundles ; the upper parts of the bundles grow 
with the leaf, and form lateral branches and branchlets, 
giving rise to the complicated system of so-called veins so 
often to be seen (especially in Dicotyledons). In many of 
the smaller phyllome structures, as scales, bracts, etc. , which 
may be regarded as rudimentary leaves, there are no fibro- 
vascular bundles, just as in the rudiments of actual leaves. 

19D.~ Venation. In mosses and other plants destitute of 
fibro-vascular bundles, the veins, when present, are composed 
of but slightly modified parenchyma ; in higher plants they 
are composed of fibro-vascular bundles and, in the larger 
veins, of one or more surrounding layers of modified paren- 
chyma in addition. The disposition of the veins in a leaf 
depends largely upon its mode of growth. Usually several 
veins form early ; if they grow from a common point, an 
arrangement like that in the maple {radiate venation) is the 
result ; if the veins grow from points on an axis, the various 
modifications of the pinnate venation are produced, depend- 
ing upon the amount of elongation of the axis. 

In many Monocotyledons the leaves continue to grow at 
their bases ; their veins are, as a consequence, parallel with 
the leaf axis ; in other Monocotyledons and most Dicoty- 
ledons the veins originate on an extending axis, and pass 
outward to or near to the margins. 



146 



BOTANY. 



191. — Leaves are for the most part bilaterally symmetrical, 
a vertical plane passing from base to apex generally dividing 
them into two equal and corresponding halves. In the elm, 
linden, begonia, etc., and the leaflets of many compound 
leaves, the two halves are unequal. The asymmetry is ap- 
parently related in some way to the position of the leaves on 
the stem, as it is more frequently noticed on plants whose 
leaves are two-ranked, with the leaf planes parallel, or 
nearly so, to the axis of the stem (or in compound leaves, to 
the central leaf axis). In some two-ranked leaves the upper 
half of each leaf (i.e.y that nearer to the apex of the stem) 
is the larger, while in others the opposite is the case.* 

192. — In form leaves are very 
variable ; even in the same plant 
it rarely happens that all have 
the same form. In general, 
elongated forms {i.e., linear and 
oblong) prevail in the Monocoty- 
ledons, while as a rule they are 
considerably broadened {i.e., 
lanceolate, elliptical, cordate, 
etc.) in mosses, ferns, and Di- 
cotyledons ; many exceptions, 
however, occur. 

193. — The absolute size of 
leaves varies greatly also. The 
largest leaves — as, for example, those of palms, tree-ferns, ba- 
nana, Victoria regia, etc. — occur in the warmer portions of 
the earth ; in frigid regions the leaves are small ; in tem- 
perate climates perennial leaves are, as a rule, smaller than 
annual ones. 




A 

Fig. 124.—^, leaf with serrate mar- 
grin ; J5, leaf with dentate or tooth ea 
margin ; C, leaf with crenate or scal- 
loped margin. 



* See an article on this subject by Professor Beal in American 
Naturalist, 1871, p. 571, and a still earlier one by Dr. Wilder. Both 
writers show that in many cases the upper half of the leaf is the most 
developed, in opposition to De Candolle, who makes the statement 
that " the side most developed is always the lower." Herbert Spencer's 
supposition that the want of symmetry is (in some cases) due to the 
shading of the smaller half of the leaf, they show not to be correct, as 
the asymmetry is observable in the voung leaves in the unexpanded 
bud 1 



OF LEA VE8 IN GENERAL. 



147 







194.— Leaves, like other members of the plant-body, may 
branch during their growth. At first they are always simple, 
and if the growth is uniform the result is a simple leaf ; if, 
however, as frequently happens, the growth is more rapid at 
certain points, branches may arise, as in the so-called com- 
pound leaves. All grada- 
tions are observable between 
simple leaves, in which the 
growth has been absolutely 
uniform (producing entire 
margins), to compound 
leaves with jointed leaflets. 
The differentiation is here 
much like that which takes 

place in passing from the ^ig- ISS-Three-iobedleaf of Hepatica. 

thallome to the form of plant-body with distinct caulome 
and phyllome. 

The simplest cases are those in which the branches are 
rudimentary, as in the serrate (Fig. 124, A), deiitate (Fig, 
124, E)^ crenate (Fig. 124, C), and other similar forms. 
When the branches are more prominent they give rise to 
lobes of various kinds (Figs. 125, 126). Where the longitu- 
dinal growth of the leaf (not of its 
branches) is but little, the lobes ap- 
pear to radiate from a common 
point, as in hepatica, mallow, maple, 
etc. ; such are called radiately, pal- 
mately, or digitately lobed. Where, 
as in the oak, the longitudinal 
growth of the leaf is considerable, 
the lobes are laterally arranged upon 
a central portion ; such leaves are 
said to be pinnately lobed. 
195. — Leaf -branches frequently become so developed that 
they themselves form distinct leaves, and thus we have .what 
is termed the compound leaf (Figs. 127 and 128). Terms 
similar to those used in the case of lobed leaves are here 
used also ; thus where the secondary leaves (leaflets) grow 
from an extremely short axis, so that they radiate fiom a 




A 

Fig. 126.—^, three-lobed sag- 
ittate leaf. B, three-lobed has- 
tate leaf. 



148 



BOTANY. 



common point, the leaf is said to be radiately, pahnately, or 
digitately compound (Fig. 127, A and B), In those cases 
where the leaflets grow from an axis which lengthens more 




Fig. 127.—^, palmately compound leaf of Horse-chestnut; ^, palmately trifoliate 
compound leaf. 

or less, the leaf is termed a pinnately compound one (Fig. 
128, A and B). It not infrequently happens that in the 
growth of leaflets they also produce branches, giving rise 
thus to doubly compound leayes. 





A B 

Fig. 128.— -4, pinnately compound leaf ; B, pinnately compound leaf, with common 
midrib prolonged and metamorphosed into a tendril. (See page 136.) 

196. — The stipules which occur as lateral appendages upon 
the petioles of many leaves of Dicotyledons are early leaf- 
branches which were not carried up by the subsequent elon- 



THE ARRANGEMENT OF LEAVES. 149 

gation of the petiole ; as in the pea, vetch, agrimony, 
quince, etc. 

§ IV. The Aerakgemekt of Leaves (Phyllotaxis). 

197. — Leaves are disposed on stems in various ways : 

(1.) They may be in wliorls of three or more encircling 
the stem at intervals. In this case each whorl was formed as 
a ring of rudimentary leaves about the punctum vegetationis.* 
The leaves of each succeeding whorl usually appear just 
above and between the preceding ones, so that the whorls 
alternate with one another. 

(2.) Where two leaves originate on exactly opposite sides 
of, and at the same height on, the punctum vegetationis, the 
opposite arrangement is produced. Here, as in whorled 
leaves, the new ones usually arise in the intervals between 
the previously formed ones, so that the pairs of leaves decus- 
sate. 

(3.) If the leaves originate singly (scattered or alternate 
leaves), the simplest case is that in which each succeeding 
leaf appears a little above the preceding and on the opposite 
side of the punctum vegetationis. In this case, where the 
stems elongate, the leaves are arranged in two opposite lon- 
gitudinal rows or ranks {ortliosticliies),\ hence this is called 
a tivo-ranlced arrangement. 

(4.) If, instead of each new leaf forming at a point half 
of the circumference of the punctum vegetationis from the 
last, it appears at a point distant (always in the same direc- 
tion) one third of the circumference, there will be three ver- 
tical rows of leaves upon the stem ; this is the tfiree-ranhed 
arrangement. 

(5.) In rare cases the succeeding leaf is in each case distant 
one fourth of the circumference from the last, always meas- 
uring in the same direction; this gives rise to tYiQ four - 
ranked arrangement. 

* There are some cases of false wliorls, in wliicli the leaves are first 
formed at different heights, and only later by irregularities in the 
growth of the stem become whorled. 

f From the Greek opiJoS, straight, and crr/;^o5, a row. 



150 BOTANY. 

(G.) It is very common for the young leaves to appear in 
succession on the punctum vegetationis at a distance equal 
to two fifths of the circumference from each, producing a 
five-ranked arrangement. 

(7.) A seven-ranhed arrangement is rarely seen; it is pro- 
duced by the leaves following each other at a distance of two 
seventlis of the circumference. 

(8.) An eight-ranked arrangement, which is a very common 
one, results from the leaves appearing at the constant distance 
of three eighths of the circumference. 

(9.) In like manner there may be formed 9, 11, 13, 14, 18, 
21, 23, 29, 34, 37, 47, 55, and 144 ranks. 

198. — The distance between any two succeeding leaves is 
called the angular divergence; it may generally (but not always) 
be deduced directly from the number of ranks (orthostichies) ; 
thus in the 2-ranked leaves it is \ ; in the 3-ranked, J ; in 4- 
ranked, ^ ; in 5-ranked, f (rarely |) ; in 7-ranked, f ; in 8- 
ranked, f (rarely -J) ; in 9-ranked, f ; in 11 -ranked, y\ ; in 
13-ranked, -f-^ ; in 14-ranked, -f^ ; in 18-ranked, y% ; in 21- 
ranked, g^- ; in 23-ranked, -^^ ; in 29-ranked, -^ ; in 34- 
ranked, if ; in 3 7-ranked, -3^- ; in 47-ranked, J^ ; i^^ ^^" 
ranked, f^ ; in 144-ranked, -f^^. 

Examples of the more common of these arrangements are to be 
found as follows .* 

{a.) 2-ranked in Fagus, Celtis, TJlmus, Vitis, Tilia, most Viciece^ and 
all grasses. 

(&.) 3-ranked in Carex, Scirpus, and most Jungermannice. 

(c). 4- ranked in the bracts of the principal axis of inflorescence of 
Mestio erectus and Thamnochortus scariosus. 

(d.) 5-ranked in Quercus, Populus, Robinia, most Rosacece, Borra- 
gwacem, etc. ; this is the most common arrangement in Dicotyledons. 

{e.) 7-ranked in Melaleuca ericoe folia, EwphorUa heptagona, Sedum 
sexangulare, etc. 

(/.) 8-ranked in Polytrichum, Parietaria erecta, Antirrhinum ma- 
jus, RapTianus, Brassica, Hieracium pilosella, etc. 

ig ) 9-ranked in Lycopodium seiago. 

{li.) 11 -ranked not rarely in JSedum rejlexum and Opuntia vulgaris. 

(A;.) 13-ranked in Verhascum, Rhus typhina, Tsuga canadensis. 

* This list of examples is from Hofmeister's " Allgemeine Morphol- 
ogie der Gewachse," p. 448 et seq. 



ABBANOEMENT OF LEA VES. 



151 



(l.) 21-ranked in the weak brandies ot Abies pectinata and Picea 
excelsa, and in most cones of these species. 

(m.) 34-ranked on strong branches of AUes pectinata and Picea 
excelsa, cones of Pinus laricio, and the interfloral 
bracts of the inflorescence* of Hudheckia. 

(n.) 55-ranked in the uppermost shoots of many 
pines and firs, in many Mamillarice, etc. 

(o.) 144-ranked in the interfloral bracts of 
strong-grown flower-heads of Heliantlius annuus, 

199. — By an examination of yarious 
leaf-arrangements, the following interest- 
ing but not very important facts may be 
noted (Fig. 129) : 

(1.) If we draw a line from the inser- 
tion of one leaf to the one next above and 
nearest to it, and continue this around the 
stem to the next, and so on, a spiral will 
be obtained agreeing with the order of 
development of the young leaves on the 
punctum vegetationis. To this line, so 
drawn, the name of Generating Spiral 
has been given. 

(2.) In most cases the spiral passes more 
than once around the stem before inter- 
secting leaves of all the ranks. 

(3.) The number of turns of the spiral 
about the stem in intersecting leaves of 
all the ranks equals the numerator of the 
fraction which indicates the angular di- 
vergence of the leaves from each other. 

(4.) Two sets of secondary spirals {Par- 
astichies)'^ crossing each other at an acute 
angle may be observed on the stem when being numbered from be- 

o J low upward. — After 

the leaves are close together, as in Fig. Pranti. 

129 ; the leaves numbered 1, 6, 11, and 16 form one of the 




Fig. 129.— Diagram of 
eight - ranked arrange- 
ment. The orthostichies 
are marked at the top 
and bottom in Koman 
numerals, I. to VIII; the 
generating spiral may be 
readily followed from 
kaf to leaf, the latter 



* It is of great importance that the student should not regard these 
spirals (generating spirals and parastichies) as anything more than 
convenient means for describing any particular leaf-arrangement. En- 
tirely too much attention has been given to working out all kinds of curi- 
ous mathematical laws, which are, to say the least, absolutely worthless 



152 



BOTANY. 




parasticliics passing to the riglit, while leaves 3, 6, 9, 12, 
Ibj 18 belong to the parastichies which pass to the left. 

(5.) Upon counting, 
in Fig. 129, it is found 
that there are three 
parastichies passing to 
the left and five to the 
right ; the smaller 
number is the same as 
the numerator of the 
fraction expressing the 
angular divergence, 
while the sum of the 
two equals the denomi- 
nator ; similar rela- 
tions may be shown to 

Fig. 130, — Diagram of eight-ranked arrange- . , . , -, 

ment, viewed from above. The orthostichies, wliich CXlSt in OtUer CaSCS. 
here appear to be radial lines, are numbered, as in nr\r\ T-P 

Fig. 129, from /. to F///. The leaves are number- ^UO. — il UOW We 

ed from 1 to 16.-After Sachs. g^^^^ ^^^ ^Q^Q^l ^Y- 

rangements by projecting the stem upon a flat surface in 

such a way that the successive 

nodes, in ascending the stem, 

are represented by smaller 

and smaller concentric circles 

(Fig. 130) (as would, in fact, 

be the case if we made sections 

through the nodes of the 

punctum vegetationis), it is 

at once evident that each leaf 

is so placed as to stand over 

the vacant space between the 

previously formed ones, and 

that as regards the leaves 

formed after it, it is equally 

well situated. 

Hofmeister formulates this 

to the morpliologist. So much has this been done, that the study of 
Phyllotaxis has in some quarters become little more than a species of 
mathematical gymnastics. 




Fig. 130a.— Cross-section of a leaf-bud 
of the Hemlock Spruce (Tsuga Canaden- 
sis). Magnified.— After Hofmeister. 



ARRANGEMENT OF LEAVES. 153 

as follows :* "ISTew lateral members have their origin above 
the centre of the widest gaps which are left at the cir- 
cumference of the punctuni Yegetationis between the in- 
sertions of the nearest older members of the same kind ;'* 
and no doubt this is one of the most important immediate 
causes which determine where each new leaf is to arise. If it 
be asked why, then, are not all leaves arranged alike, the 
answer must be looked for in the differences in structure of 
the punda vegetationes. In cases where there is an apical 
cell, the arrangement of the leaves may be directly traced to 
its mode of division. In Phanerogams it is often clearly due 




rig. 1305.— Cross-section of the leaf-bud of the chestnut {Castaneavesca). v^, r)K 
the scale-lilce leaves ;/^/2,/3, etc., the rudimentary leaves ; s^-s^, s'^-s'^, etc., the 
stipules belonging to" the correspondingly numbered leaves. Magnified. — Aftej 
Hofmeister. 

to a difference in the size and form of the punctum vegeta- 
tionis ; in Conifers and Composites, for example, it is com- 
mon for a change in the arrangement to take place in pass- 
ing from the foliage leaves to the bracts of the inflorescence 
upon the same stem, the number of ranks in such cases 
being greater on the larger axes. Doubtless some of the dif- 
ferences can be explained only by taking into account, also, 
the inherited peculiarities of the plant. 

* "Allgem. Morphol.," p. 483, and quoted in Sachs' "Text-Book," 

p. 177. 



154 



BOTANY 



A study of iicliuil cross-sections of leaf -buds will make the 
truth ois tlic previous statements more clearly evident. Hof- 




Fig. 130c. — Cross-section of a lateral htifl of the Virginia Creeper (Ampelopsis quirv' 
Quefolia)^ showing arrangement of pans in a double bud. Magnified.— After Hof- 
meieter. 

meister's figures,* several of which are here reproduced (Figs. 

130, a, to 130, d), show 
that in all cases the leaf 
rudiments occupy in 
the bud the j^ositions in 
w^hich they meet with 
the least resistance. 
This is beautifully 
shown in the leaf-bud 
of the Hemlock Spruce 
(Fig. 130, a). In the 
leaf-bud of the chest- 
nut (Fig. 130, b), the 

Fig. 130^.- cross-section of the leaf-bud of a ^^^^^ «^^P^^^^^ ^^'"^ ^^^^ 

young plant of Indian corn (Zea mats). I., the bud-SCalcS 'I but here, aS 

cotyledon, with its two fibro-vascular bundles, 1, V; . ^ 

i/., 77/., /F., F:, the successive leaves, their mid- m the precedmg CaSC, 

ribs marked by a dot. Magnified.— After Hofmeis- ,, i p n 

ter. growth appears to loilow 

the ^nines of least resistance," the young leaves occupying 
the interspaces between the stipules. The double lateral bud 




* In " Allpiem. Morpliol. 



INTEBNAL STEUGTURE OF LEAVES. 155 

of the Virginia Creeper (Fig. 130, c) may also be studied with 
profit, and it is curious to see how the positions of some of the 
leaves are altered by the fact that the bud is a double one. 
The bud of the Indian corn (Fig. 130, d) shows that the same 
law holds in the Monocotyledons as in the Dicotyledons. 

§ V. The Iitteri!^al Structure of Leayes. 

201, — The internal structure of leaves varies considerably. 
In all cases, however, the leaf is composed mainly of thin- 
walled, chlorophyll-bearing parenchyma, and this is to be re- 
garded as the proper leaf tissue. The fibro-vascular bundles 
constitute little more than the framework of the leaf and 
its connection with the 

stem, while the epider- -«==*.^*^==T \ \ e 
mis is here, as elsewhere 

in the plant, a covering 1 \ \ || 1\ W^&[»^ — ^ 

tissue. In the related 
members of the plant, 
such as bracts, scales, 
floral envelopes, and 

other phyllome struc- ^AS^^^-^^yKi^ r^3^^C"^^ 
tures, chlorophyll-bear- 
ing parenchyma is gen- CY^_y ] P\,£'''¥^^riSS' 

erally wanting, but 

from true leaves it is Fig. ISl.— Vertical section of a portion of the leaf 

TQvnl-vrovov Q"hapnf Tlip oi Echinocustis lobcifa. «, epidermis of the upper 

rareiy ever aosent. xne g^^face ; e\ epidermis of the lower surface ; /the 

shaiDe of the leaf, its parenchyma constituting the " palisade " tissue ; 

^ . , 2/, the loose and irregular parenchyma of the lower 

size, position, and re- P^irtof theleaf. in a part of the section the chlo- 

-, ,. , ,1 rophyil granules are shown. X 250.— From a 

lation to other mem- drawing by J. C. Arthur. 

bers, all have somewhat to do with securing the best disposi- 
tion of the essential leaf tissue. 

202. — In leaves composed of one layer of cells, as in many 
mosses and some ferns, obviously there is no need of any 
special arrangement of the cells in order to secure their best 
exposure to light, heat, gases, etc. In thick leaves, however, 
the internal cells are clearly not so well situated as the 
external ones are, hence we find such leaves possessing some 
peculiarities in their structure which obviate this difficulty." 
Instead of being composed of solid tissues,^ their cells are 




156 



BOTANY. 




generally loosely an-anged, with large intercellular spaces be- 
tween tlicin (Figs. 131 and 133), and these are in free com- 
munication with tlie external air by means of the stomata. 
It most frequently happens that this loose tissue is in the 
under part of the leaf, while the 
upper portion is composed of one or 
more layers of closely placed cells ; 
and tliis agrees with the general 
distribution of the stomata, there 
l)oing usually many more on the 
under than the u|iper surface. 

203. — The upper denser tissue, 
termed 'palisade tissue, is composed 
of elongated cells, which stand at 
right angles to the surface of the 
leaf (Fig. 131). In cross-section the 
palisade-cells are cylindrical, with 
small intercellular spaces between 
them (Fig. 132), or in some cases 
they are more or less compressed and angular. 

In general, palisade tissue is confined to the upper surface 
of the leaf, the lower being occu- 
jned by the loose tissue previously 
mentioned ; but there are some cu- 
rious exceptions to this rule. The 
most notable of these is found in 
the leaf of Silphium laciniafum — 
the so-called Compass Plant * — of 
the Mississippi Yalley ; its chloro- 
phyll-bearing parenchyma is almost 
entirely arranged as palisade tissue, 
so that the upper and lowei' por- 
tions are almost exactly identical 
in structure (Fig. 134). The ver- 
tical leaves of the Manzanita of 
the Pacific Coast {A7^ctostaphylos pungenSj var. platypTiylla) 
have a similar structure. 



Section of tne " pali- 
eade " tissue of the leaf of Echi- 
vocystis lobata, taken parallel to 
the leaf surface. A few of the 
cells drawn with their contained 
chlorophyll granules. X 250. — 
From a drawing by J. C. Arthur. 




Fig. laS.— Section of the loose 
parenchyma of the leaf of Echino- 
cystis lobata, taken parallel to the 
leaf t-urface. Several of the cells 
are drawn showing their chloro- 
phyll granules. X 250.— From a 
drawing by J. C. Arthur. 



* For iescriptions of this curious plant, wliose leaves have a marked 
tendency to stand with one edge to the north and the other to the 



INTERNAL STRUCTUBE OF LEAVES. 



157 



204. — Another curious leaf structure is to be seen in 
Stipa spartea, the Porcupine Grass of the interior ; each long 
harsh leaf is longi- 
tudinally channel- 
led on its upper 
surface, which, by 
the twisting of the 
basal portion of 
the leaf, becomes 
apparently the low- 
er, and the chlo- 
rophyll-bearing pa- 
renchyma is con- 
fined to the sides of 
tlie channels (Figs. 
135 and 136). At 
the bottom of each 
channel the epider- 
mal cells are pe- 
culiarly developed 
into a hygroscopic 
tissue, which, by 
contracting, closes 
the channels and 
rolls the leaf to- 
gether, as always 
takes place in dry 
air. 

{a) Many Monocoty- 
ledons — as, for exam- 
ple, Iris and Indian 

nnvn ftflPriT-rl rtnr,A ot^o ^ig- 134.— Transverse section of the leaf of Silphium 

corn— <iuoiu ^ooa bpe- ladniatum. e, epidermis of the upper surface ; e\ epi- 

cimens of very young dermis of the lower surface ; p, palisade tissue of the 

lAQTroo "Rv^ ^QTofiillTT- upper portion of the leaf; p\ palisade tissue of the 

ieavtJB. x>y cd,reiuiiy lo^^r part of the leaf ; s, a Ptoma seen in transverse 

removing the outer section. X 235. —From a drawing by the author, 
leaves in succession all stages of leaf-development may be obtained. 




south — i.e., with, the leaf-planes parallel to the plane of the meridian- 
see articles in the American Naturalist : 1870, p. 495 ; 1871, p, 1 ; 
18?7,p.48tt. 



158 



BOTANY, 



(6) Among Dicotyledons 




In tliis way often much light will be thrown upon the morphology 

of leaf parts.* 

it is generally best to select those whose 
young leaves are least downy or hairy, 
otherwise the difficulties of the examina- 
tion are greatly increased. The lilac is 
one of the best for this purpose. Longi- 
tudinal sections, prepared as in the ex- 
amination of young stems, should be 
made. 

(c) The young leaves in the winter buds 
of the hickory are instructive, as showing 
how compound leaves are formed. 

{(l) The study of the arrangement of 
leaves is most interesting in the twigs 

and cones of the Conifers, and the stems and heads of the Composites. 

The student should, however, before spending much time in the 



Fig. 135.— A part of a trans- 
verse section of the leaf of Stipa 
spartea in the position it as- 
eumes— i.e., with what is really 
the upper surface turned toward 
the earth. /,/, ribs, each con- 
taining a fibro-vascular bundle ; 
between these are the mas.^es of 
chlorophyll-bearing parenchyma 
(figured dark in the cut), x 18. 




Fig. 136.— Transverse section of one of the ribs of the leaf oi Stipa spartea. tp, 
chlorophyll-bearing parenchyma ; s, s, portions of the epidermis containing stomata ; 
he, he, hygroscopic cells, which contract when the leaf rolls up. The blanK space on 
the left shows the extent of the cavity occupied by chlorophyll-bearing parenchyma. 
X 125 — From a drawmg by the author. 

examination of the more difficult forms, study the twenty-sixth section 

of Sachs' *' Text- Book of Botany," and the whole subject of the 



* In illustration of this, the Iris itself may be cited. Its leaf is 
usually spoken of as made by the folding of its upper surface upon 



THE ROOTS OF PLANTS. 159 

arrangement of lateral members as given in Hofmeister's " General 
Morphology." * 

(e) The internal structure of the leaf may be easily studied The 
most Important sections are those made at right angles to the surface ; 
but some should be made also parallel to it, so as to show the forlu of 
the palisade cells and the dispositions of the cells in the loose tissue of 
the under surface. The leaves of the lilac, apple, cherry, Impatiens, 
SUpMum, sunflower, etc., are very good for this study. The more 
difficult sections can be more easily made after soaking the leaves for 
some time in strong alcohol, thus hardening them. 

§ YI. Of the Eoots oe Plants. 

205. — The root differs from all other members of the 
plant in being tipped with a peculiar mass of cells — the Root- 
cap {pileorhiza f ) — and in originating endogenously ; from 
stems it difiers in never producing leaves or other phyllome 
structures. There is some doubt as to whether the Primary 
Koot — i.e., the first root of the embryo — is not in many cases 
formed otherwise than endogenously ; X but all common roots 
certainly are developed from beneath the surface of other 
parts of the plant. 

206. — Eoots may develop from any part of a plant which 
contains fibro-vascular bundles, so that it is no uncommon 
thing for them to issue from stems (particularly their nodes) 
and leaves, as well as from other roots. Whatever their 
origin, they are essentially alike, the differences, as before 
intimated, being of minor importance. They all agree in hav- 

itself, so that the two sides exposed to the air and light are said to be 
in reality the under surface. A study of the very young leaf of the 
Iris, along with that of Hemerocallis, shows them to be alike ; both are 
composed of an upper laterally flattened portion and a lower channelled 
one ; in the Iris the upper portion grows fully as much as the lower, 
while in Hemerocallis Wie growth is almost entirely confined to the lower 
portion, the upper extending but little and forming the small extremity 
of the leaf. Th^ small tip of the leaf in the latter case is clearly the 
homologue of the whole of the so-called ensiform leaf of the former, 

* " Allgemeine Morphologie der Gewachse," von Wilhelm Hofmeis- 
ter ; Leipsig, 1868. 

f From the Greek irlXeoS, a cap, and /Si'Ca, a root. 

j The mode of formation of the Primary Root will be taken up for each 
group of plants in Part II. 



ICO 



BOTANY, 



ing less perfectly developed tissues and tissue systems. Their 
epiderraid system is iiioi'o feebly developed, and they bear A^ery 




rig. 137.— Longitudinal section through the apes of a root of Indian com {Zea 
mai£). All v?ithin and above the line v, s, v. is the root proper, all below and outside 
of it ie the root-cap, or piUorhiza ; s, apex of root ; e, e, epidermis, continued into 
the dermatogen at the apex ; r. v. the thickened outer wall of the epidermis (the 
origin of the root-cap from the dermatogen is not shown in this figure) ; x. 7\ the cor- 
tex which is produced from the periblem at the apex ; ?«, g.f, the plerome ; m be- 
comes the pith, ff a vessel, /, wood ; a, a. outer and older portion of the root-cap ; i, 
inner and younger portion of the root-cap.— After Sachs. 



THE BOOTS OF PLANTS. 161 

simple tricliomes^the root-hairs. The fibre- vascular bun- 
dles are, especially in the higher plants, of a much lower 
type than those in the stems and leayes. The fundamental 
system is also poorly deyeloped, and has not that variety of 
tissues found in other portions of the plant. 

207. — Another remarkable peculiarity of roots is that they 
differ much less from one another in structure than do their 
stems. The young roots of Monocotyledons have very nearly 
the same structure that those of Dicotyledons have, and those 
of Pteridophytes do not differ much from either. The older 
roots of Monocotyledons and Dicotyledons differ considerably, 
on account of changes in their structure which take place 
later, and then each root bears a closer resemblance to the 
stem from which it grows, or to which it belongs. 

208. — The general structure of the root-cap may be easily 
understood from the accompanying figure (Fig. 137). It is 
a cap-like mass of parenchymatous cells which surrounds 
the end of the root ; its outer cells are loose, and in some 
cases are more or less changed into a mucilaginous mass; 
in any event they gradually lose their protoplasm and become 
detached and destroyed. The inner layers {i, s, Fig. 137) are 
constantly developing from a deep-lying tissue, the Dermato- 
gen* (not shown in the figure), so that as the cap is destroyed 
on the outside it is renewed from the interior. By its lat- 
eral growth it in some cases ensheathes the terminal part of 
the root for a considerable distance. 

209. — Back of the root-cap lies the primary meristem of 
the root, composed, in Phanerogams, of a mass of small and 
actively dividing cells. In this meristem there is as yet no 
differentiation, but as it is prolonged by rapid cell-multipli- 
cation the cells become modified in its posterior portion. 
There is thus a constantly advancing formation of meristem, 
followed at a little distance by as constant a modification 
into other tissues. The usual course of this differentiation 
is first into a central cylindrical mass, the Plero7ne\ (Fig. 

* From tlie Greek Sip/na, SepjuaroS, skin, and ysvvucj, to bring forth or 
generate. 

f So named by Hanstein (" Scbeitelzellegruppe im Vegetationspunkt 
der Phanerogamen/' 1868), from the Greek ttTitj pu/ia. a filling up. 



162 



BOTANY. 



137, m,f, g), whicli is enslieathed by the Per ihlem* whicli 
soon becomes transformed into the cortical portion of the 
root (x, r, Fig. 137). The epidermis is developed from the 
region from which the root-cap grows, and, in fact, as will 
be shown below, it is a continuation and modification of the 
generating tissue of the root-cap. 

210. In Fig. 138 the relation of the parts is even better 

shown than in !he previous figure. The central plerome 
column is surrounded by a layer of active cells, the pericam- 




Fig, 138.— Median longitudinal section of the apex of the root of the buckwheat 
{Fagopyrum esGulentum). pc, pericambium, constituting the boundary of the plerome 
column ; e, dermatogen ; between e and^^c, periblem ; h, root-cap. — After De Bary. 

bium [pc) ; outside of the latter lies the periblem, or young 
cortical portion, and still outside of this the dermatogen 
(e),*'which further back on the root becomes the epidermis. 
The root-cap (Ji) lies entirely outside of, and is quite distinct 
from, the back portions of the dermatogen, but near the 
apex of the root there is a tract in which dermatogen and 
root-cap apparently fuse into one. At this point the layers 

* Another of Hanstein's terms, from the Greek nepiSTuj/za, a clrak. 



THE ROOTS OF PLANTS. 



163 



of the root-cap originate by tlie successive divisions of the 
dermatogen cells by partitions parallel to the curved surface 
of the root-tip. As the dermatogen is continuous with the 
epidermis, we may regard the root-cap as morphologically 
a greatly thickened and somewhat modified epidermis. 




Fig. 139.— Mode of formation of the lateral roots in a mother-root of Trapa natans. 

A, a portionof the pericambium tt, bounded externally by the innermost layer of cor- 
tical ceUs, r; d, dermatogen ; n, the inner layer of the pericambium after splitting ; 

B, the same advanced somewhat, the inner layer is beginning to divide ; C, young 
root enclosed in the tissue of the mother-root ; B. r, cortex of mother-root ; tt, peri- 
cambium of mother-root, from vs^hich the new root has been formed ; A, first layer of 
th« root-cap of the new root, formed by the splitting of its dermatogen b ; ^, n, mass 
of cells resulting from the division of the layer nin A ; D, new root further devel- 
oped (the thick cortical tissues of the mother-root are not shown ; r, inner layer of 
cortical tissue of mother-root) ; "p, p, periblem of new root ; m, m, the tissue which 
connects the new root with the tissues of the mother-root. Magnified.— After 
Reiuke. 

The plerome column is a mass of nascent fibro-vascular 
elements, and in it, somewhat further back from the root-tip, 
a differentiation into the bundle takes place. 



1C4 BOTANY. 

211. — The formation and development of a new root is 
interesting and suggestive. It usually takes place at some 
distance from tlie primary meristem, in the cambium or peri- 
cambium. In the root of Trapa natans it takes place as fol- 
lows : The cells of a restricted portion of the pericambium 
divide by tangential walls into an outer layer, which becomes 
the dermatogen of the new root {d, Fig. 139), and an inner 
layer, from which develops its primary meristem {n, Fig. 
139). Tlio inner cells multiply by divisions in several direc- 
tions, and as their mass increases they push out the young 
dermatogen {B, C, and D, Fig. 139). From the dermato- 
gen the first layer of the root-cap is formed by the tangen- 
tial division of its cells {C, h, Fig. 139). These growing 
tissues push out the overlying portions of the mother-root, 
and finally break through them. The root is thus seen to 
be a strictly endogenous formation ; there is no connection 
between its tissues and the epidermal and cortical portions 
of the mother-root, the sole connection being with the deep- 
lying tissues in, or in connection with, the fibro-vascular 
bundles. Herein roots present a marked contrast to stems 
and leaves, which, as a rule, develop from the exterior of 
the plant-body, or, in other words, are exogenous in their 
origin. 

212. — Eoots ai'e rarely arranged in as regular an order as 
are stems. In general they arise in acropetal order upon the. 
mother-roots of Pteridophytes and the primary roots of Phar 
nerogams, but this order is subject to many more disturbing 
influences than in the case of the origin of stems. As to 
position, they may arise in rows or ranks, or in particular 
spots, dependent upon the disposition of the fibro-vascular 
bundles, or the generating tissues in the root or stem. Thus 
it may happen that on a root or stem there may be as many 
rows of roots as there are fibro-vascular bundles. Eoots 
which develop from stems are generally much more affected 
by external influences than those which grow from othei 
roots. The degree of moisture of the different parts of the 
stem appears to have much to do in determining the point 
of the appearance of roots ; this is seen in stems which toucli- 
the ground, as in the tomato, and in climbing plants, as the 



THE ROOTS OF PLANTS. 165 

Ivy {Hedera), Poison Ivy (Rhus), tlie Virginia Creeper {Am- 
pelopsis), etc. 

213. — In form roots are generally fibrous, and this is 
manifestly their best form, in so far as they are organs for 
obtaining dissolved matters from the soil. In perennials, 
however, as the stems become larger the roots increase cor- 
respondingly to support the additional weight ; they thus 
become hold-fasts or mechanical supports. In other cases 
they are made the recipients of assimilated matters, as starch, 
sugar, etc., and thus become thickened storehouses. 

In many cases the latter are capable of forming buds and 
of sending out new stems from the meristem tissue in, or in 
the vicinity of, the fibro-vascular bundles, as is notably the 
case in the tuberous root of the sweet potato. 

{a) The root-cap may be studied with the least difficulty in roots 
which are grown in water. Those of Lemna may be easily obtained,^ 
and are excellent. 

(6) Roots of Indian corn, Hyacinth, Impatiens, etc., also furnish, 
easily made and good specimens. 

(c) In preparing specimens for examination thin longitudinal sections 
should be made, and these should be supplemented by transverse sec- 
tions taken at various heights on a root-tip. 

{d) By the use of staining fluids, as carmine, magenta, etc., some 
points in the structure will be made more evident. Iodine should also 
be used ; by treatment with it, the starch which is present in the root- 
tip in many, if not all, cases may be seen. 

(e) For studying the formation and development of new roots suc- 
culent plants should be chosen, as the sections of their tissues are more 
transparent than those of other plants. On this account many water 
plants are to be preferred. Among land plants, Impatiens is one of 
the best; it always has a large number of forming roots on its stem 
near or at the surface of the ground. 

(/) Vertical sections of the papillae, showing the point of appearance 
of new roots, should be made. If many longitudinal slices of the 
lower part of the stem of Impatiens are made in a section-cutter, it will 
almost certainly happen that some good specimens will be found. 



CHAPTER X. 

THE CONSTITUENTS OF PLANTS. 

§ I. The Water ik the Plant, 

214.— Amount of Water in Plants. All living parts of 
plants are abundantly supplied with water. It is always 
present in living protoplasm, and the greater its activity the 
more watery is its composition. The cell-walls of living 
tissues also contain large quantities of water ; and in plants 
composed of many cells (as the larger flowering plants) even 
those cells and tissues which have lost their activity generally 
have their walls saturated with water. In ordinary herbace- 
ous land plants the amount of water is not far from 75 per 
cent of their whole weight ; thus in growing rye it is about 
73 per cent ; in meadow grass, before blossoming, 75 — after 
blossoming, 69 ; in lucerne, when young, 81 — in blossom, 74 ; 
in white clover, 80 ; in red clover, before blossoming, 83— 
after blossoming, 78 ; in oats, in blossom, 81 ; in Indian 
corn, in blossom, 84. In certain parts of plants the per- 
centage is still higher ; for example, in the leaves of the field 
beet it is 90 ; in tubers of the potato, 75 ; in the thickened 
root of the parsnip, 88 ; in the similar root of the turnip, 
92. In aquatic plants the percentage is much higher, often 
exceeding 95 ; it is so abundant in many .of the simpler 
forms that upon drying nothing but an exceedingly thin and 
delicate film is left. 

215.— Water in the Protoplasm. As explained in para- 
graphs 4 and 5 (page 5), living protoplasm has the power 
of imbibing water, arid thereby of increasing its fluidity. 
Even after it has imbibed all the water which it can retain 
it continues the process, and separates the surplus in drops 



THE WATER IN THE PLANT. 167 

in its interior, the so-called vacuoles. Now an examination 
of the cells of rapidly growing tissues shows that their pro- 
toplasm is much more watery than that of living, but dor- 
mant tissues — e.g. , those of seeds — and one of the first signs 
of activity in the latter is the imbibition of water. 

This avidity of protoplasm for water plays an important 
part in the general economy of the plant. By it all the cells 
which contain protoplasm are kept turgid, and by the ten- 
sion thus created the soft parts of plants are made rigid. 
It plays no small part also in keeping up the supply of 
moisture in living tissues when wasted by evaporation. (See 
paragraph 220 et seq. ) 

216.— Water in the Cell- walls. In the cell-walls, accord- 
ing to Nageli's theory, the water forms thinner or thicker 
layers surrounding the crystalline molecules of cellulose. (See 
paragraph 37, p. 32.) The wall of the cell is thus not a 
membrane which separates the water of one cell cavity from 
that in the next, but rather a pervious stratum, composed of 
solid particles which are not in contact, and between which 
the water freely passes. In a living tissue the water is con- 
tinuous from cell to cell, and constantly tends to be in equi- 
librium — i.e., the turgidity of the cells is approximately 
equal throughout the tissue, and likewise the wateriness of 
both cell-walls and cell-contents. 

In the simpler aquatic plants the water of the cells and 
their walls is continuous with that in which they grow. 
Likewise the water in the tissues of roots or other absorbing 
organs of the higher aquatic plants is continuous with that 
which surrounds them; and even in ordinary terrestrial plants 
there is a perfect continuity of the water in the root tissues 
with the moisture of the soil. 

217.— Water in Intercellular Spaces. In some cases the 
intercellular spaces and passages, and even the vessels of the 
more succulent plants, are filled with water, thus increasing 
its amount in the whole plant very considerably. More 
commonly, however, these cavities are filled with air and 
gases, the vessels having early lost the protoplasm which 
they contained at first. It is probable, moreover, that the 



168 BOTANY. 

water which is occasionally found in their cavities has little 
or no physiological relation. 

218.— The Equilibrium of the Water in the Plant. The 
water in the tissues of every plant tends constantly to become 
in equilibrium, and this state would soon be reached were it 
not for certain disturbing causes which are almost as con- 
stantly in action. In any cell an equilibrium may soon be 
reached between the two forces which reside respectively in 
the cell-wall and the protoplasm, viz., (1) the attraction of 
the surfaces of the molecules for the water, and (2) the 
* imbibition power" of protoplasm. This equilibrium once 
attained, all motion of the water must cease, and it must 
remain at rest until disturbed by some other force or forces. 
This condition, or one approximating veiy closely to it, is 
reached by many of the perennial plants during the winter 
or period of rest. 

219.— Disturbance of Equilibrium. During the growing 
stages of plants the equilibrium of the water is constantly 
disturbed in one or more ways, viz., (1) by the chemical 
processes within the cells ; (2) by the '' imbibition power" of 
the protoplasm and walls of newly formed cells ; (3) by the 
evaporation of a portion of the water. 

The chemical processes within the cell include : (1) the 
actual use of water by breaking it up into hydrogen and 
oxygen ; every molecule which is so broken up leaves a 
vacancy which, sooner or later, must be replaced ; (2) the 
formation of substances which are more soluble than those 
from which they were formed ; (3) the formation of sub- 
stances which are less soluble than those from which they 
were formed. These processes take place in all cells, even 
those of the simplest plants. 

In plants composed of tissues, wherever new cells are 
forming and developing, the new protoplasm and cell-walls 
require considerable quantities of water to satisfy their 
molecular attraction (paragraphs 215 and 216 above) ; this 
supply is always made in part or entirely at the expense 
of the adjacent cells. In many aquatic plants there can 
be little doubt that the needed water in meristem tissues 
is obtained partly by direct absorption from the surround- 



THE WATER IN THE PLANT. 169 

ing water, but this can only be the case with the external 
cells ; the deep-lying ones must obtain their supply from the 
cells which surround them. In aerial parts of plants the 
newly formed cells obtain all their water from the adjacent 
cells. 

220.— Evaporation ofWater. In the aerial parts of plants 
the evaporation of water from their surfaces is a far more 
powerful disturbing cause than either of the two preceding. 
Whenever a cell is exposed to dry air at ordinary tempera- 
tures a portion of its water passes off by evaporation ; this 
immediately disturbs the equilibrium of water throughout 
the tissue, and the more rapid or the longer continued the 
evaporation, the greater the disturbance. 

Evaporation (called also transpiration and exhalation) 
from living cells or tissues is dependent upon a number of 
conditions, some of which are entirely exterior, while others 
are connected with the structure of the plant itself. Among 
the former, the most important is the condition of the air as 
to the amount of moisture which it contains. In air satu- 
rated with moisture no evaporation can take place ;* but 
whenever the amount of moisture falls below the point of 
saturation, if the other conditions are favorable, evaporation 
takes place. The temperature of the air (and, as a conse- 
quence, that of the plant also) has some effect upon the 
rapidity of evaporation. It appears that there is an increase 
in the amount of water given off as the temperature rises ; 
this may be due, however, to the fact that with such increase 
of the temperature of the air there is generally a considerable 
decrease in its moisture. The direct influence of light upon 
evaporation is also somewhat doubtful. While there can be 
no doubt that plants generally lose more water in the light 
than in darkness, it may be questioned whether this is not 



* Many experiments, at first sight, seem to sliow tliat plants evapo- 
rate water in air saturated with moisture ; but Knop lias found 
^" Versuchs-Stationen," Vol. VI., p. 255) that, under similar conditions, 
moist pieces of paper or wood also evaporate water, thus showing that 
the air, instead of being saturated, lacked somewhat of being so. 



170 BOTANY. 

mainly due to the increased heat and dryness which are 
common accompaniments of the increase of hght.* 

221. — In enumerating the internal conditions one general 
one must not be forgotten, which is, that the water in plant- 
cells contains many substances in solution, and consequently 
evaporates less rapidly than pure water, in accordance with 
well-known physical laws. Moreover, the attraction of the 
molecules of the cell-walls for the water layers counteracts, 
to a considerable extent, the tendency to evaporation ; and 
in the same manner, even to a greater extent, the water is 
prevented from passing off by the "imbibition power" of 
protoplasm. It is, in fact, impossible to deprive cellulose 
and protoplasm of their intermolecular water in dry air at 
ordinary temperatures. 

In all the aerial parts of higher plants the epidermis 
offers more or less resistance to the escape of the water of the 
underlying tissues. This is mainly accomplished by the 
thick and cuticularized outer wall of the epidermal layer ; in 
many cases, especially in plants growing naturally in very 
dry regions, the epidermis consists of several layers of cells, 
which offer still more resistance to evaporation by being 
themselves filled with moist air only. Among the lower 
plants, the single reproductive cells (spores) are guarded 
against the loss of water by having their walls greatly thick- 
ened and cuticularized. Even in the lowest plants, the Slime 
Moulds (Myxomycetes), the naked masses of protoplasm, 
when placed in dry air, will contract into rounded masses, 
which then become covered with a somewhat impervious 
envelope (paragraph 23, c : page 21). 

222. — The stomata of the green and succulent parts of 
higher plants control to a great extent the amount and 
rapidity of their exhalation. In leaves, for example, where, 
on account of its cuticularization, there can be but little 
evaporation through the epidermis, it is dependent upon the 



* I am aware that some experiments made with plants in saturated 
find in dry air appear to show that in direct sunlight there is a rapid 
evaporation. I cannot, however, regard these experiments as con^ 
elusive. 



THE WATER IN THE PLANT. 171 

number, size, and condition {i.e., whether open or closed) 
of the stomata. As previously described (paragraph 130, p. 
99), the stomata are placed over intercellular spaces, which 
are in communication with the intercellular passages of the 
plant. These spaces and passages are filled with moist air 
and gases, which, when the stomata are open, expand and 
contract with every change of temperature or atmospheric 
pressure, and thus permit the escape of considerable amounts 
of water ; when, on the other hand, the stomata are closed, 
little or no escape of moisture is possible. The openmg and 
closing of the stomata appear to depend upon the amount of 
light ; they open more widely the greater the amount of 
light, and close almost completely in darkness. The amount 
of moisture on the surface of the epidermis appears also to 
affect somewhat the opening and closing of the stomata ; 
when the epidermis is very dry the stomata are generally 
closed, and vice versa. 

223.— The Amount of Evaporation. The conditions con- 
trolling evaporation are thus seen to be many and various. 
They never, or but very rarely, act singly, two or more of 
them usually acting together with varying intensity, so that 
the problem of the amount of evaporation taking place at 
any particular time is a complex and difficult one. All the 
observations yet made, and which have necessarily been upon 
a very small scale, indicate that the rate of evaporation is 
actually very slow. Thus Hales long ago found that the 
amount of water evaporated from a vine in twelve hours of. 
dayhght equalled a film only .13 mm. (.005 in.) thick, and 
having an extent as great as that of the evaporating surface ; 
the amount from a cabbage in the same time equalled a film 
.31 mm. (.012 in.) thick ; from an apple tree, .25 mm. (.01 
in. ) thick ; from a sunflower in a day and a night, equal to 
a film -15 mm. (.006 in.) thick.* Mtiller found the rate of 
evaporation from the leaves of Hcemmithus puniceus to be 
only one seventeenth as rapid as that from an equal area of 
water during the same time. Sachs found the evaporation 

* " Statical Essays : Vegetable Statics," by Stepben Hales. 1727. 
Fourtb edition. 1769. p. 21. 



172 BOTANY. 

from the leaves of the White Poplar to be about one third as 
rapid as from water. linger places the evaporation from 
most leaves at about one third that from equal areas of 
water ; in some cases, however, running as low as one fifth 
and one sixth. * 

224. — Pfaff calculated the amount of water evaporated 
from an isolated oak tree during the growing season. The 
tree selected was a close-topped one 6| metres (20 ft. ) high, 
bearing about 700,000 leaves. The results were as follows : 

May (14 days) 883 kilograms = ( 1,944 lbs.) 

June '. 26,023 " =(57,250 " 

July 28,757 " =(63,265" 

August 21,745 " =(47,839" 

September 17,674 " =(38,882" 

October 17,023 ♦' = (37,450 *' 

The evaporation from each leaf was for the season of five 
and a half months (one hundred and sixty-seven days) .16 
kilograms (.35 lbs.) ; allowing forty-eight square centimetres 
of surface to each leaf, this amounted to a layer of water 
3.33 centimetres (1.31 in.) deep over the whole evaporating 
surface. \ 

225.— The Movement of Water in the Plant. It is clear, 
from what has bfeen said, that in polycellular plants there 
must be a considerable movement of water in some parts, to 
supply the loss by evaporation. Thus in trees there must be 
a movement of water through the roots, stems, and branches 
to the leaves, to replace the loss in the latter. This is so 
evident that it scarcely needs demonstration ; it can, how- 
ever, be shown by cutting ofP a leafy shoot at a time when 

* The three last statements and the following are given on the 
authority of Ducbartre (" Elements de Botanique," second edition, 1877, 
pp. 844 and 846). 

f Pfaff found that the water evaporated during the season, when con- 
sidered with reference to the area of ground covered by the tree top, 
was equal to a layer 5.39 metres high (212 inches). Observation had 
shown the annual rain-fall to be .65 metres (25.6 inches) ; so that the 
■water evaporated from the tree was eight times the amount which fell 
upon the earth under it. The evaporation is very much less in dense 
forests than in isolated trees, but with every allowance it is suflBcient 
in dry, hot seasons to quickly exhaust the moisture of the soil. 



THE WATER IN THE PLANT. 173 

evaporation is rapid ; in a short time tlie leaves wither and 
become dried up, unless the cut portion of the shoot be 
placed in a vessel of water ; in the latter case the water will 
pass rapidly into the shoot, and the leaves will retain their 
normal condition. If in such an experiment a colored watery 
solution (as of the juice of Poke berries) be used instead of 
pure water, it will be seen that the liquid has passed more 
abundantly through certain tracts than through others, in- 
dicating that the tissues are not equally good as conductors 
of watery solutions. As would readily be surmised, the 
tissues in ordinary plants which appear to be the best con- 
ductors are those composed of elongated wood-cells, and it is 
doubtless through them that the greater part of the water 
passes. Furthermore, it is probable that the movement of 
the water is through the substance of the cell- walls, and not, 
at least to any great extent, through the cell cavities. Ac- 
cording to this view, the force which raises the water, in 
some cases to the height of a hundred metres or more, is the 
attraction of the surfaces of the crystal molecules for the 
layers of water which surround them. 

226. — The rapidity of the upward movement of water evi- 
dently varies directly as the rapidity of evaporation, and in- 
Tersely as the area of the conducting tissue in transverse sec- 
tion. As both these factors are variable, it is impossible to 
give an average rate of movement. Sachs estimated the 
rate of ascent in a branch of the Silver Poplar, from which 
there was strong evaporation, at 23 cm. (9 in.) per hour. 
McJSTab, by watering plants with a solution of lithium citrate 
and then examining the ashes at successive points, found the 
rate in a Cherry Laurel to be 101 cm. (40 in. ) per hour. Pfit- 
zer obtained the astonishing result of 22 metres (72 ft.) per 
hour in the Sunflower ; there is but little doubt, however, 
that this is entirely too high. 

{a) In addition to the movements of the water described above, that 
which has been called root pressure requires a brief mention. If the 
root of a vigorously growing plant be cut off near the surface of the 
ground and a glass tube attached to its upper end, the water of the root 
will be forced out, often to a considerable height. Hales* noted a pressure 

* Statical Essays, p. 114, 



174 BOTANY. 

upon a mercurial gauge equal to 11 metres (36.5 ft.) of water when at- 
tached to the root of a vine ( Vitis). Clark,* in a similar manner, found 
the pressure from a root of the birch {Betula lutea) to be equal to 25.8 
metres (84.7 ft.) of water. This root pressure appears to be greatest 
when the evaporation from the leaves is least ; in fact, if the experi- 
ment is made while transpiration is very active, there is always for a 
while a considerable absorption of water by the cut end of the root, 
due probably to the fact that the cell-walls had been to a certain ex- 
tent robbed of their water by the evaporation from above. Root pres- 
sure is probably a purely physical phenomenon, due to a kind of en- 
dosmotic action taking place in the root- cells. 

(b) The flow of water (sap) from the stems and branches of certain 
trees, notably from the Sugar Maple, appears to be due to the quick 
alternate expansion and contraction of the air and other gases in the 
tissues from the quick changes of temperature. The water is forced out 
of openings in the stem when the temperature suddenly rises ; when 
the temperature suddenly falls, as at night, there is a suction of water 
or air into the stem. When the temperature is nearly uniform, whether 
in winter or summer, there is no flow of sap. 

§ II. As TO SOLUTIOis^S. 

227. — The water in the plant holds in solutron several 
substances, so that it is not water alone, but in reality a 
complex solution. Some of the substances in solution are 
solids, as the inorganic salts taken up from the soil or water, 
while others are gaseous, as the air and carbon dioxide taken 
up in the water by the roots, or absorbed by the leaves and 
there entering into solution in the water. The final use of 
these solutions will be spoken of farther on ; here it is only 
necessary to point out some of the more important general 
facts as to solution and diffusion : 

1st. "When a substance has entered into solution it still 
exists as that substance, and the water in which it is dis- 
solved is in one sense pure. Tliis is readily shown by driving 
off the water by heat, when the dissolved substance is again 
obtained in its original solid state. 

2d. As soon as solution begins the process of diffusion 

* In 1873, recorded in the Twenty-first Report of the Secretary of 
the Massachusetts State Board of Agriculture. See also further re- 
sults by the same observer in the Twenty-second Report. 



PLANT FOOD, 175 

necessarily commences also ; this is the passage of the mole- 
cules of the dissolved substance through the water without a 
movement of the latter. Thus in perfectly quiescent water 
a substance may diffuse itself between the molecules of the 
latter to considerable distances, and this may take place in 
any direction, even when the substance is heavier than water ; 
thus common salt placed in the bottom of a tall vessel of 
water will dissolve and gradually diffuse throughout the 
whole. 

3d. The rapidity of diffusion varies for different sub- 
stances ; thus the diffusion rate of sugar is more than three 
times that of common salt (exactly as 365 to 116). 

4th. Two or more diffusions may take place at the same 
time in the same fluid, and they may move in the same or in 
opposite directions. 

5th. Diffusion continues until all parts of the solution 
contain equal quantities of the dissolved substance. 

6th. If at any point in a solution the dissolved substance 
be removed in some way, as, for example, by the formation 
of a new salt by chemical reaction, there will be, as a conse- 
quence, a continued diffusion toward that point ; and if the 
new salt be a soluble one it must diffuse in every direction 
from the point of its formation. Thus the molecular move- 
ments may become quite complex. 

§ III. Plant Food. 

228.— The most important elements which are used in 
the nutrition of plants, or which, in other words, enter into 
their food, are Carbon, Hydrogen, Oxygen, Nitrogen, Sul- 
phur, Iron, and Potassium. These all appear to be necessary 
to the life and growth of the plant, and if any of them are 
wanting in the water, soil, or air from which the plant de- 
rives its nourishment, death from starvation will soon follow. 
There are other elements which are made use of by plants, 
but as life may be prolonged without them, they are regarded 
as of secondary importance. In this list are Phosphorus, 
Calcium, Sodium, Magnesium, Chlorine, and Silicon. 



176 BOTANY. 

229.— The Compounds Used. With the single exception 
of oxygen, the elementary constituents named above do 
not enter into the food of plants in an uncombined state ; 
on the contrary, they are always absorbed in the condition 
of compounds, as water, carbon dioxide, and the 

Nitrates "^ f Ammonia. 

Sulphates | Potash. 

C'arbonates ( qP J Lime. 
Phosphates | 1 Iron, 

Sihcates, or | Soda, or 

Chlorides J [ Magnesia. 

In addition to these, many organic compounds are ab- 
sorbed in particular cases, as in those plants which live in 
decaying animal or vegetable matter (saprophytes), as well 
as those which absorb the juices from living plants (para- 
sites). 

230. — How the Pood is Obtained. — In the case of aquatic 
plants, these compounds are taken into the plant-body by a 
process of diffusion from the surrounding water ; in terres- 
trial plants the gaseous compounds, as carbon dioxide and 
carbonate of ammonia, are' absorbed — at least in part — by the 
leaves directly from the surrounding air, while the solutions 
of these and the other compounds in the water in the soil 
find their way into the plant by diffusion. 

230a.— How the Food is Transported in the Plant. 
Once within the plant-body, the food materials diffuse to all 
watery parts, in the case of the larger terrestrial plants ris- 
ing through the stem to the leaves. By diffusion, there is a 
constant tendency toward an equal distribution throughout 
the plant of the solutions which enter it, and if there were 
no disturbing chemical reactions taking place, such a condi- 
tion would in most plants be soon reached. It is quite 
probable, indeed, that this actually happens for certain sub- 
stances which are found in solution in the soil or water, and 
which, entering plants, diffuse through them to all parts, 
but not being used they soon reach a state of equal diffusion, 
which is only slightly disturbed by the extension of the 
plant-body by growth. Doubtless the rapid diffusion of 
food materials throughout terrestrial plants is aided by the 



PLANT FOOD. 177 

evaporation of water from the leaves, thus causing a strong 
upward movement of the water which contains the various 
solutions of food matter. Moreover, there can be no doubt 
that the movement of the water in terrestrial plants, caused 
by the swaying and bending of the stems and branches, 
facilitates and hastens the diffusion of food materials. 



CHAPTER XI. 

CHEMICAL PROCESSES m THE PLANT. 
§ I. Assimilation. 

231. — In many plants the food materials whicli are taken 
into the plant-body are of such a nature that they can be 
directly used by the protoplasm ; thus in the saprophytes 
the solutions of organic compounds derived from the decay 
of animal or vegetable tissues are imbibed by the protoplasm 
and used by it as true food ; and in the parasites the proto- 
plasm and the juices of living tissues are directly used in a 
feimilar way. It is, furthermore, probable that in some of 
the lowest forms of vegetation, as in the Myxomycetes and 
Schizomycetes, the protoplasm is capable of making, to a 
limited extent, a direct use of some of the inorganic sub- 
stances absorbed by them. For the most part, however, the 
principal food materials taken in by plants are such as can- 
not be directly used by protoplasm in either its vegetative 
or reproductive activity ; thus neither water nor carbon 
dioxide is directly used as food by the protoplasm of ordi- 
nary green plants, but in all cases they undergo certain 
chemical changes, by which they are made suitable for use 
by protoplasm. The most important of these chemical 
changes is Assimilation, in which carbon dioxide and water 
axe transformed into a hydrocarbon. 

232. — It is impossible as yet to give a complete statement 
of all the processes in assimilation ; the principal facts now 
made out appear to be as follows : In the chlorophyll- 
bearing portions of plants, carbon dioxide and water are de- 
composed, and from their component elements carbohydrates 
are at once formed. This decomposition and subsequent 
combination take place only in the granules or masses of 



METASTASIS. 179 

cUorophyll, and only in sunlight. Those parts of ordinary 
plants which are destitute of chlorophyll are entirely want- 
ing in the power of assimilation, and likewise the chloro- 
phyll-bearing portions are unable to assimilate in darkness. 
Carbon dioxide is probably decomposed into carbon oxide 
and free oxygen : CO^ = CO + 0. At the same time water 
is decomposed into hydrogen and oxygen : H^ = 2 H + 
0. The free oxygen atoms are exhaled, and by the union 
of carbon oxide and hydrogen, starch is in most cases 
formed ; this appears as minute granules imbedded in the 
chlorophyll-bodies (Fig. 43, p. o2). In some plants no 
starch is formed in the chlorophyll, but oily or sugary mat- 
ters which have nearly the same chemical significance. 
Assimilation is thus a deoxidizing process. Both water and 
carbon dioxide contain large quantities of oxygen, while in 
starch it is much less ; consequently, in the formation of the 
latter from the former, there must be a surplus of oxygen. 
This may be shown as follows : 



12 CO, =|}|g 
12H,0 = jl|g 



CO ^ starch 

24 O set free. )- — C12 H20 Ojo -1- 2 Ha O, 



Here twelve molecules of carbon dioxide and twelve mole- 
cules of water produce one molecule of starch and two mole- 
cules of water (water of organization), while twenty-four 
atoms of oxygen are set free and permitted to escape from 
the cells into the surrounding air or water. 

§ II. Metastasis. 

233.— Its General Nature. The chemical changes just 
described, which constitute assimilation, take place only in 
chlorophyll-bearing plants, or parts of plants, and in these 
only in the sunlight. In cells which are destitute of chloro- 
phyll, and in the chlorophyll-bearing ones in the absence of 
light, other chemical changes take place ; these, while differ- 
ing much among themselves, agree in always being processes 
of oxidation, and changes of one organic compound into an- 
other To these chemical changes, in order to distinguish 



180 BOTANY. 

them from those of assimilation, the term Metastasis* (or 
preferably Metaholism) has been applied. 

It is even more difficult to give anything like a complete 
account of the processes of metastasis than of those of assim- 
ilation all that can be done is to indicate the general nature 
of the chemical changes which are best known. 

234.— Transformation of Starch. In darkness the starch 
which had previously formed in the chlorophyll-bodies at 
once undergoes changes which render it soluble, alloAving it 
to diffuse to other parts of the plant with great freedom. 
The nature of these changes appears to vary somewhat in 
different plants, but they consist essentially in the transform- 
ation of the insoluble starch into a chemically similar but 
soluble substance. Glucose (C^^ ^^24 ^la)? inulin (C^^ H^^ O^J, 
and cane sugar (0^^ H^^ 0„) are the more common of the 
soluble substances so formed, and one or other of these may 
frequently be detected in the adjacent cells after the disap- 
pearance of the starch from the chlorophyll. 

235.— The Nutrition of Protoplasm. These diffusing as- 
similated matters are imbibed by the protoplasm of the living 
tissues, and constitute its most important food. In connec- 
tion with the nitrates and sulphates, also imbibed, they 
furnish the materials for the increase of protoplasmic sub- 
stance in growing cells. The exact changes which take 
place in the formation of j^rotoplasm are unknown, but it is 
probable that a portion of the soluble assimilated matter 
(glucose, inuline, etc.) is broken up by the action of oxygen 
into carbon dioxide and one of the organic acids {e.g., oxalic 
acid) ; and the latter, by replacing the acids in the sulphates 
and nitrates, may set free the sulphur and nitrogen necessary 
to the formation of protoplasm. The occurrence of crystals 
of calcium oxalate in the tissues of many plants rather indi- 
cates the probability of this or a similar series of reactions. 



* Literally "to place in another way," from the Greek ^erd beyond, 
or over, and hrdvai, to place. We owe the present application of the 
word to Professors Bennett and Dyer, who used it as the equivalent 
of the German " Stoffwechsel" in their English translation of Sachs' 
^Lehrbuch.*' 



METASTASIS. 181 

236,— The Storing of Reserve Material. In many plants 
the surplus of assimilated matter is stored up in one or more 
organs as reserve material ; thus in tlie potato the starch 
formed in the leaves in sunlight is, in darkness, transformed 
into glucose, or a substance very nearly like it, and in this 
soluble form it is diffused throughout the plant, and in the 
vinderground stems (tubers) is again transformed into starch. 
So in the case of many seeds a mass of reserve material is 
stored up, generally in the form of starch (e.g., the cereal 
grains), and sometimes in the form of oily matters {e.g., the 
seeds of Orucifer^, Flax, Castor Bean, Cucurbitacese, etc.). 
In the storing of starch a notable feature of the changes which 
take place is the apparent addition and subtraction of one 
or two molecules of water ; it is probable, however, that in 
the transformation of starch to glucose oxygen combines 
with some of the carbon, forming free carbon dioxide, as 
follows : 

6 (0,, H,, 0,„) + 24 = 5 (0,, H,, 0,,) + 12 CO,. 

T*he transformation of glucose to starch may be a simple 
process of breaking up of a molecule of the former into starch 
and two molecules of water, as follows : 

In the storing of oily matters it is probable that these are 
formed at the expense of the starch, and that they are the 
results of subsequent deoxidation. 

237.— The Use of Reserve Material. In the use of re- 
serve material, as in. the germination of a starchy seed, the 
starch appears to undergo a change exactly like that in its 
disappearance from chloroj)hyll. Here it is certain that oxy- 
gen is absorbed, and that carbon dioxide is evolved, while 
the starch is transformed into glucose (see the reaction above). 
Similar transformations doubtless take place in the use of 
the starch stored up in buds, twigs, stems, bulbs, etc. In 
the germination of oily seeds, after the absorption of oxy- 
gen, starch is (in many cases, at least) first produced, and 
from this the soluble sugar is formed. In any case, after the 
solution is attained the subsequent metastatic changes are 



182 BOTANY. 

similar to those which follow the transformation of the 
starch of the chlorophyll. 

238.— The Nutrition of Parasites and Saprophytes is 
similar to that of embryos, buds, bulbs, etc. Here assimi- 
lated materials are drawn from some other organism, and 
subsequently undergo metastatic changes. In some cases the 
parasitism is only partial, as in the mistletoe, where a part 
of the assimilated matter is formed in the parasite (which, 
therefore, contains chlorophyll), while a portion seems to be 
taken along with the mineral salts from the host plant. So, 
too, there are plants which are partially saprophytic in habit, 
deriving a part of their nourishment as sajorophytes, while 
the remainder is elaborated by their chlorophyll. Many cul- 
tivated plants, as we grow them, are partially saprophytic, 
deriving a portion of their nourishment from decaying or- 
ganic matter in the soil. The so-called Carnivorous plants, 
as Drosera, Dionaea, Sarracenia, Darlingtonia, Nepenthes, 
TJtricularia, etc., are in reality partially sa^orophytic, obtain- 
ing a considerable part of their food materials from de- 
caying animal matter. 

239.— The Formation of Alkaloids. Among the most 
obscure of the metastatic changes are those which give rise 
to the alkaloids. These are compounds of carbon, hydro- 
gen, nitrogen, and generally oxygen, in w^hich the first two 
elements have approximately an equal number of atoms, 
while the last two have also a nearly equal but much smaller 
number. 

The more important ones are the following : 

Conia (Cg H15N,) from Conium. 
Nicotine (Cio H14N2) from Tobacco. 
Cinclionia (C20 H24 N2O) from Peruvian Bark. 

Morpliia (C17 H19 NO3 + H2 0) from the Opium Poppy. 
Strychnia (C21 H22 N2 O2) from the seeds of Strychnos. 
Caffeine (Cg Hio N4 O2 + H2 O) from Coffee and Tea. 

These and many others occur in plants in combination 
with organic acids, such as : malic acid (C^ H^ J ; tartaric 
acid (0, H3 0,) ; citric acid (C^ H^ 0,) ; oxalic acid (0, H 
0,); tannic acid (C,, H,, 0,,) ; q^^i^ic acid (C, ia,^ J ; 
meconic acid (0, H, 0,). These acids are probably formed 



METASTASIS. 183 

by the oxidation of some of the saccharine or amylaceous 
substances in the phxnt, while the alkaloids with which they 
are combined appear to have some relation to the nitrogenous 
constituents of the protoplasm, and are possibly derived from 
them. From the fact that the alkaloids are formed more 
abundantly in those tissues which have passed the period of 
their greatest activity, it may be surmised that they are 
either compounds of a lower grade which are formed instead, 
of the ordinary albuminoids, or the first results of the incip- 
ient decay of the cells. 

240.— Results of Metastasis. In the preceding para- 
graphs it is seen that chlorophyll-bearing plants absorb 
carbon dioxide and exhale free oxygen, the former being de- 
composed in the chlorophyll granules in sunlight and the 
oxygen being set free as a consequence. In other words, the 
absorption of carbon dioxide and the exhalation of oxygen 
are connected with the process of assimilation. It is further 
seen that oxygen is absorbed and carbon dioxide evolved, as 
results of certain metastatic processes which take place in 
any tissues, whether possessing chlorophyll or not, and inde- 
pendently of the presence or absence of sunlight. In the 
sunlight the absorption of carbon dioxide to supply assimila- 
tion is so greatly in excess of its exhalation as a result of 
metastatic action, that the latter is unnoticed. In dark- 
ness, however, when assimilation is stopped, the exhalation 
of carbon dioxide becomes quite evident. So, too, with 
oxygen ; in the sunlight the excess of its evolution is so 
great over its absorption that the latter was long unknown ; 
but in the absence of light its absorption becomes manifest. 
Parasites and saprophytes, as well as those parts of ordinary 
plants which are wanting in chlorophyll, as flowers and many 
fruits, deport themselves in this regard exactly as chloro- 
phyll-bearing organs do in darkness. 



CHAPTER XII. 

THE KELATIONS OF PLANTS TO EXTEENAL 
AGENTS. 

§ I. Temperatuee. 

241— General Relations. The functions of plants are 
possible only between certain limits of temperature of the 
air, water, or soil, varying considerably for each species. In 
every plant there is a certain minimum temperature, below 
which all functional activity ceases ; thus in most instances 
plants become inactive when the temperature approaches 
0° Cent. (32° Fahr.). On the other hand, there is a maxi- 
mum beyond which activity ceases ; this ranges in different 
plants from about 35° to 50° Cent. (95° to 122° Fahr.). Be- 
tween these two extremes is the temperature at which the 
greatest activity takes place ; this has been termed the 02:)ti' 
mum. 

In any particular plant, the maxima, optima, and minima 
are not exactly alike for all functions, some being performed 
at temperatures considerably above or below those at which 
others cease. It is furthermore to be observed that, in gen- 
eral, there is a simple suspension of activity at temperatures 
a few degrees below the minimum, whereas above the max- 
imum the death of the organ ensues ; in the former a resto- 
»,-ation of the normal temperature is soon followed by a re- 
sumption of activity ; in the latter the activity cannot be 
lestored, even under the most favorable conditions. 

242o— Absorption of Water as Affected by Temperature. 
The absorption- of water and watery solutions is greatly 
affected by changes in the temperature of the absorbing 
organs, as the roots of the higher plants. Thus Sachc 
found ^Hhat the roots of the tobacco-plant and gourd no 



TEMPERATURE. 185 

longer absorb sufficient water to replace a small loss by evap- 
oration in a moist soil, having a temperature of from 3° to 
6° Cent. (37° to 41° Fahr.) ; tlie heating of the soil to a tem- 
perature of from 12° to 18° Cent. (53° to 64° Fahr.) sufficed 
to raise their activity to the needful extent.''* According 
to the same investigator, the roots of the turnip and cabbage 
continue to absorb water, even when the temperature of the 
soil is reduced very nearly to 0° Cent. (32° Fahr.). In the 
winter and early spring, when the temperature of the soil is 
low, the roots of trees and other perennials cannot absorb 
moisture unless they extend deep enough to reach the 
warmer strata beneath ; under such circumstances, it not in- 
frequently happens that if the air temperature rise high 
enough to allow evaporation, evergreen trees and shrubs are 
killed by too great loss of moisture. 

243.— Evaporation or Transpiration. In aerial plants, 
when the temperature of the air is low, but little evaporation 
takes place from the leaves or other living organs, while an 
increase of temperature is followed by an increase in the 
rapidity of evaporation. It is probable that this is due (1st) 
to the closing of the stomata in the lower, and their opening 
in the higher temperature, and (2d) to the fact that in all 
ordinary cases, as the temperature of the air is lowered its 
degree of saturation is increased, and as its temperature is 
raised its degree of saturation is decreased. As transpiration 
appears to be a purely physical phenomenon, we scarcely 
need expect it to be as definitely or certainly affected by 
changes of temperature as are the proper functions of the 
plant. 

244.— Assimilation. The lower limit of the temperature 
in which assimilation is possible varies much in different 
plants. The '' Red-snow Plant " (Protococcus, sp.) of the 
Arctic regions grows rapidly upon the surface of the snow in 
a temperature which must be little, if any, above 0° Cent. 
(32° Fahr.) ; in the larch, assimilation takes place at from 
0.5° to 2.5° Cent. (33° to 36° Fahr.), and in meadow-grasses 
at from 1.5° to 3.5° Cent. (35° to 38° Fahr.). In water- 

* " Lehrbuch." English ediiiou. p 652. 



186 BOTANY. 

plants the lower temperature limit is apparently somewhat 
higher than in aerial ones ; thus in Hottonia palustris it is 
2.7° Cent. (37° Fahr.) ; in Vallisneria, 6° Cent., or more (42° 
Fahr.) ; in Potamogeton from 10° to 15° Cent. (50° to 59° 
Fahr.). 

Neither the maximum nor the optimum temperature has 
been determined for ordinary land plants ; in Hottonia 
palustris, an aquatic plant, the maximum temperature for 
assimilation is, according to Sachs, between 50° and 56° 
Cent. (122° and 132° Fahr.). 

245.— Metastasis. But little is accurately known as to 
the effect of an increase or decrease of temperature, within 
moderate ranges, upon those metastatic changes which take 
place in the ordinary growth of plants or the storing of reserve 
material. It is well known, however, that some plants live 
wholly in low temperatures, performing all their functions 
in air or water little, if any, above the freezing j)oint. 
Thus in the '^ Ked-snow Plant," above cited, the metas- 
tatic changes must take place very near 0° Cent. 

In the polar waters, where the temperature is from 3° to 
5° Cent. (37° to 41° Fahr.), or even less, myriads of diatoms 
flourish, and in seas but little warmer many of the higher 
sea-weeds (Fucaceae and Floridese) abound. In all these 
cases the metastatic changes (as well as all others) must take 
place at these low temperatures. In ordinary land-plants it 
is to be observed that whereas assimilation takes place only 
during the light part of the day, when it is warmer, metasta- 
sis takes place not only in daylight, but even more rapidly in 
darkness, when the temperature is considerably lower. * 

Sachs measured the length of plumule developed upon 
different plants of the same species subjected to different 
temperatures, and in this way found the approximate optima 
for several species, as folloAvs \\ 



* It must not be forgotten, however, that assimilation is dependent 
upon light, while metastasis is somewhat checked by it, and this is 
doubtless by far the most important relation ; and still it is a significant 
fact that in ordinary land-plants metastasis continues when assimi- 
lation has stopped. 

fin " Physiologische Untersuchungen iiber die Abhangigkeit der 



TEMPERATURE. 



18? 



Pea 36° Cent. (78.8° Fahr.). 

Wheat (winter var.) 34° " (92.7° " 

Indian corn 34° " (92,7° 

Scarlet Bean 34° " (92.7° "• 

In Sachs' and others' observations upon the growth of 
roots, it was found that the most rapid growth took place 
for different plants at the following temperatures : 

Scarlet Bean 26° Cent. (78.8° Fahr.). 

Pea... ^^-^^ " (79-9° " 

Flax 27.4° " (81.3° " 

Wheat (winter var.) 28.5°" (83.3° " 

Barley (summer var.) 28.5° " (83.3 

Indian corn 34° " (92.7° 

In the deposit of reserve material there can be no doubt 
that metastasis often takes place at lower temperatures than 
assimilation ; thus the storing of starch in the potato tubers, 
and in many other subterranean stems and roots, takes place 
in the soil which, at the time, is much cooler than the air. 

In the growth of many plants in early cpring, at the ex- 
pense of reserve material in the roots or stems, the metas- 
tatic changes often take place at quite low temperatures. 
Thus perennial and biennial rooted plants, as many grasses, 
thistles, parsnips, etc., begin to grow almost as soon as the 
snow has disappeared, and the flower buds of many perenni- 
als develop equally early — e.g., the hazel, elm, maple, liver- 
leaf (Hepatica), Mayflower, etc. 

As regards the metastatic changes which take place in the 
germination of seeds, we have much more definite informa- 
tion. Sachs has determined the minimum, optimum, and 
maximum temperatures for tho germination of the seeds of 
the following plants :* 





Minimum. 


Optimum. 


Maximum. 


Ind. corn. 
Scar. B'n.. 
Pumpkin. 
Wheat. . . 
Barley. . . 


9.4° C.r= (48.8° F.). 
9.4° C.= (48.8° F.). 
14° C.:= (56.7°F.). 
5° C.:r.(41° F.). 
5° C.= (41° F.). 


34° C. = (92.7° F.). 
34° C. = (92.7° F.). 
34° C. = (92.7° F). 
29° C. = (83.7° F.). 
29° C. =: (83.7° F.). 


46° C. = (115.2° F). 
46° C. = (115.2° F.). 
46° C. = (115.2° F.), 
42° C. = (108.5° F.). 
37° C. = ( 99.5° F.). 



Keimung von der Temperature," in " Pringsheim's Jahrblicher ftir 
Wissenschaftliche Botanik," Vol. II., 1860, p. 354. 
■^ " Physiologische Untersuchungen," etc., op. cit., p. 365. 



188 



BOTANY. 



According to several observers, the minima and optima 
for the germination of the seeds of the following plants are : 





Minimum. 


Optimum. 


Lepidium sativum 

Flax 


1.8° C. = (35° Fahr.). 
1.8° C. = (35° " 
0.0° C. = (32° " 
6.7° C. = (43° *' 


27.4° C. = (81° Fahr.). 
27.4° C. - {81° " 


White Mustard 

Pea 


27.4° C. = (81° 
26.6° C. = (80° 
31.5° ('. = (88.7° 
31.5° C. = (88.7° 
31 5° C — C88 7° 




Pole Bean 




Sunflower 












Watermelon 




37.5° C. = (99.5° ' 









246.— Death Caused by High Temperature. AYhen the 
temperature rises above a certain point the death of the 
plant takes place. Tnose plants, or parts of plants, which 
contain the least water are capable of enduring higher tem- 
jDeratures than those which are more watery. Thus at from 
65° to 80° Cent. (149° to 177° Fahr.) many dry spores and 
ceeds are uninjured, while in water they are generally killed 
when the temperature exceeds 50° or 55° Cent. (122° or 131° 
Fahr.). For ordinary growing parts of plants the tempera- 
ture must be, as a rule, considerably lower than those given 
r.bove. Few aquatic plants can endure a prolonged tempera- 
ture much, if any, above 40° Cent. (104° Fahr.), and at 50° 
Cent. (122° Fahr.) most terrestrial plants are soon killed. 
It appears, also, that at temperatures much lower than these 
Gome plants arc killed ; thus, according to Hofmeister," the 
organization of the protoplasm of the plasmodium of Didy- 
onium serpula (one of the Slime Moulds) is destroyed by 
heating it, in air, to 35° Cent. (95° Fahr.), and in the nearly 
related Fuligo varians the same destruction follows at 39° 
Cent, (102° Fahr.). 

The immediate cause of death appears to be the coagula- 
tion of the albuminoids of the protoplasm. The protoplasm 
thus loses its power of imbibing water, and the cells conse- 
quently lose their turgidity. In watery tissues chemical 
changes at once begin, resulting in the rapid disintegration 



* " Die Lehre von der Pflanzenzelle," 1867, p. 27, 



TEMPERATURE. 189 

of the substances in the cells, accompanied by an eyolution 
of carbon dioxide. 

247.— Death Caused by Low Temperature. In many 
respects the results of too great a reduction of temperature 
are similar to those produced by too great an elevation. 
There is obseryed the same coagulation of the albuminoids, 
resulting in the destruction of the power of the protoplasm 
to imbibe water, and, as a consequence, in the loss of the tur- 
gidity of the cells. Moreoyer, as in the case of injury from 
high temperature, those celis which are the most watery are 
the ones which, other things being equal, are injured most 
quickly by a reduction of temperature. Embryo plants in 
seeds, when dry, are able to endure almost any degree of low 
temperature ; but after they haye germinated, and the cells 
haye become watery, they are generally killed by a reduction 
to, or a few degrees below, 0° Cent. (32° Fahr.). So, too, 
the comparatiyely dry tissues of the winter buds and ripened 
stems of the natiye trees and shrubs in cold countries are 
rarely injured eyen in the severest winters, while the young 
leaves and shoots in the spring are often killed by slight 
frosts. 

Death from low temperature is always accompanied by the 
formation of ice-crystals in the succulent tissues ; these, are 
formed from the water of the plant, which is abstracted from 
it in the process of congelation. Much of the water thus 
frozen is that which fills the cavities (vacuoles) of the cells, 
while some of it is that which moistens the protoplasm and 
cell-walls. Now it is evident that the water in the large 
vacuoles is much more easily congealed than that in the pro- 
toplasm and cell- walls ; for in the latter the force of adhesion 
between the molecules of protoplasm or cellulose and the 
imbibed water offers a considerable resistance to the separa- 
tion of the water in ice-crystals, and this resistance is greater 
as the contained water is less. As the liquid in the vacuoles 
is not pure water, but a mixture of several solutions, it freezes 
at a lower temperature than water, and then, according to a 
well-known law of physics, separates into pure ice-crystals 
and a denser unfrozen solution. By a greater reduction of 
temperature more ice-crystals may be separated out, and th^ 



190 BOTANY. 

remaining solution made denser still. These adhesive forces 
tend to retard the formation of ice-crystals, and it is prob- 
able that it is only in extremely low temperatures, if at all, 
that the liquids in the \A'Mvt are completely solidified. 

248. — A plant which has been frozen may survive in many 
instances if thawed slowly, whereas if thawed quickly its 
vitality is generally destroyed. Thus many herbaceous 
plants will endure quite severe freezing if they are afterward 
covered so as to secure a slow rise of the temperature, and 
many bulbs, tubers, and roots will survive the severest win- 
ters if covered deej)ly enough to prevent sudden thawing. 
Likewise turgid tissues, which are not living, as those of 
many succulent fruits, are injured or not by freezing, accord- 
ing as the thawing has been rapid or slow. From these facts 
it may be inferred that the injury in freezing is primarily of 
a physical instead of a chemical nature, and that it is mainly 
the withdrawal of water from its physical union with the 
solids of the cell. According to this view, the difference be- 
tween slow and rapid thawing is that in the former the 
slowdy liquefying water is reabsorbed by the same solids from 
which it had been abstracted, while in the latter the large 
amount of water set free is imperfectly absorbed, forming 
solutions which are unstable and subject to subsequent fer- 
mentive changes. It is probable that to these fermentive 
changes is due the coagulation of the albuminoids and 
the rapid disorganization of the protoplasm which accom- 
pany injury from freezing. 

While the sketch given above is doubtless true in a large 
number of cases, it appears that in many other cases death 
follows freezing whether the thawing be rapid or not ; and 
this indicates that besides the immediate causes of death al- 
ready indicated, there are others which are as yet unknown 
CO us. 

§ 11. Light. 

249.— General Relations. Directly or indirectly plant- 
life, as indeed all life, whether vegetable or animal, is de- 
pendent upon light. Parasites and saprophytes may grow 



LIGHT. 191 

in complete darkness, but tliey do so at the expense of ma- 
terial which has been elaborated in light. So, too, some 
parts of many ordinary plants grow in total darkness, as 
roots, tubers, bulbs, etc., but these depend for their carbo- 
hydrates upon the aerial, chlorophyll-bearing parts which 
are in the light. As will be shown in the sequel, this depen- 
dence of all life upon light is due to its relation to chloro- 
phyll in the processes of assimilation ; and while other func- 
tions than that of assimilation and other orgars than those 
which contain chlorophyll are somewhat affected by the 
presence or absence of light, or its greater or less intensity, 
yet these latter are of comparatively little moment when com- 
pared with the former. 

The absorption of water by the plant appears to be entirely 
independent of light, and in most plants it takes place in its 
entire absence. Likewise it is probable that light itself does 
not directly affect the rate of evaporation of water from the 
leaves of higher plants. As, however, the stomata are gen- 
erally opened more widely in light than in darkness, evajDO- 
ration may be promoted by it in some cases. 

250.— Light and Assimilation. It is first of all to be 
observed that chlorophyll itself is dependent upon light. 
Those parts of plants (with rare exceptions) which grow in 
darkness are destitute of chlorophyll, and even parts which 
contain chlorophyll lose it when placed for some time in com- 
plete darkness. When such a colorless plant is brought into 
the light it soon becomes green from the formation of chlo- 
rophyll in its protoplasm. 

The decomposition of carbon dioxide, and the consequent 
evolution of oxygen, only take place in the light. As the 
light decreases in intensity from a certain point the amount 
of assimilation decreases ; on the other hand, there is a de- 
crease in assimilation as the intensity increases unduly, and 
beyond certain points in either direction assimilation ceases. 
Thus there are here, as in the case of temperature, a mini- 
mum, optimum, and maximum ; but we cannot define their 
limits as readily, for want of a proper instrument. 

251. — Experiments have often been made upon plants 
when placed in rays of different refrangibility, and it has 



1^2 BOTANY. 

been sliown (1) that the assimilation is greater in the wliolo 
beam (white light) than in any one of its constituent rays, 
and (2) that the amount of assimilation varies greatly in the 
different rays.* When plants arc grown in the different 
rays of the spectrum, and properly protected, so that each 
receives but one kind of light, the amount of assimilation in 
each case is about as follows, that for white light being 100 : 



Red, 


Orange, 


Yellow, 


Green, 


Blue, 


Indigo, 


Violet, 


9.5 


23.5 


37.3 


14. 


8.2 


5. 


2.5 



The less refrangible rays are thus seen to be far more effica- 
cious than the more refrangible ones, and in the yellow and 
orange rays, which are the biightest to the eye, the greatest 
amount of assimilation takes place. From these rays there 
is a decrease toward each end of the visible spectrum, and in 
the so-called heat rays and chemical rays, found respectively 
beyond the red on the one hand and the violet on the other, 
there is no assimilation whatever. 

252.— Light and Metastasis. Many of the metastatic 
changes in the plant take place in complete darkness, such 
as those connected with the growth of roots and other sub- 
terranean organs. In trees and thick-barked shrubs the metas- 
tatic changes which occur in the stems are in total darkness, 
and even in many herbs the thick cortical tissues must cut 
off the greater part of the light from the active interior cells. 
On the other hand, in a great number of aquatic plants their 
translucency is so great that every internal change must be 
in bright light, and in a few terrestrial plants — as, for ex- 
ample, in Imjmtiens Balsamlna — the cortical tissues permit 
most of the light to penetrate to the inner active cells. These 
facts indicate a marked indifference of the metastatic changes 
to light, as compared with those of assimilation. 

This indifference is further illustrated in the growth of 
flowers in the dark, where, with few exceptions, they develop 
as perfectly as in the light. So the colorless parasites — e.g., 
Monotro'pa, Ajohyllon, Corallorliiza, etc. — and all the fungi 

* The earliest experiments of much value were those of Charles 
Daubeny, " On the Action of Light upon Plants, and of Plants upon 
the Atmosphere," pub. in Phil. Trans., 1836. 



HELIOTROPISM. 193 

grow either in light or darkness. It must not be inferred, 
however, that there is a complete indifference to the presence 
or absence of light, for careful experiments show that light 
favors some metastatic changes, while in many cases it actu- 
ally exerts a retarding influence. Thus if all other condi- 
tions, as temperature, moisture, etc., are made constant, the 
rapidity of growth of most aerial stems is considerably greater 
in darkness than in light ; while under similar conditions 
thie growth of the leaves of most plants is less. Experiments 
show that the retardation of growth is due to the rays of 
high refrangibility, blue, indigo, violet, and ultra violet, and 
that, so far as the metastatic changes under consideration 
are concerned, the less refrangible rays are equivalent to 
darkness. 

§ III. Helioteopism. 

253. — The retarding influence of light n23on the growth 
of stems gives rise to a curvature when the illumination is 
stronger upon one side than upon the other. Thus, as is 
well known, most plants, when grown in windows, bend 
strongly toward the light, and if their position be afterward 
reversed they soon bend again toward the side of greatest 
illumination. To this phenomenon, which is an exceedingly 
common one throughout the vegetable kingdom, the name 
Heliotropism* has been giveii. The explanation which is 
commonly given is that the light retards the growth on the 
illuminated side, while the shaded side elongates, resulting 
in a tension which necessarily produces a curvature. 

254. — Evidently allied in some way to heliotro23ism is the 
bending of certain organs mu ay from the light. Thus the 
leafless stems (runners) of Saxifraga sarmentosa, when grown 
in a window so that they are illuminated upon one side more 
strongly than upon the other, curve toward the darker side. 
This opposite bending has been called Negative Heliotro- 
pism, and is supposed to be caused by light in some way not 
yet understood. The tendrils of the Vine and Virginia 

* From the Greek fjlio'i, the sun, and Tpeneuv, to turn. 



194 BOTANY. 

Creei^er {Ainpelojjsis) are negatively heliotropic, and they 
are thus enabled to reach and attach themselves to the sur- 
faces — e.g., walls, tree-trunks, etc. — which give them sup- 
port. The same organ may be positively heliotrojoic in one 
stage of its growth and negatively so in another ; thus the 
younger internodes of the ivy {Hedera) bend toward the 
light, and the older ones away from it ; and the runners of 
Saxifraga sarmentosa, mentioned above, are positively he- 
liotropic as soon as they develop tufts of leaves upon their 
free extremities. 

The rays of light which cause the curvature are those 
having the greatest refrangibility. Sachs' experiment shows 
this conclusively ; he grew plants in light which had jiassed, 
on the one hand, through a solution of potassium bichro- 
mate, and, on the other, through one of ammoniacal coj)per 
oxide ; in the light passed through the first solution (red, 
orange, and yellow rays, and a portion of the green) there 
was no curvature whatever, Vv^hile in the blue, indigo, and 
violet rays passed through the second solution the heliotro- 
pic curvature was strongly shown. 

g ly. Geotropism. 

255» — N'early all organs of plants have a definite, normal 
direction of growth, which is in general terms, either toward 
or away from the earth. Thus the plasmodium of Fuligo 
varians creeps upward ; the conidia-bearing hyphae of moulds 
grow upward, while the root-like hyphae grow downward ; the 
stems of many mosses grow upward, and their rhizoids down- 
ward ; in the higher plants the stems, as a rule, grow upward, 
some root-stocks and other stems growing downward, how- 
ever, while the roots, as a rule, grow downward. To these 
phenomena of growth the name Geotropism* has been 
given ; when the direction of growth is downward, the organ 
is said to be positively geotropic, when upward, negatively 
geotropic. 

Knight long ago proved gravitation to be the cause of 

* From the Greek yij, yea, tlie earth, and rpeireiv, to turn. 



GEOTBOPISM. 195 

geotropism. * He placed germinating seeds npon wheels, 
which were made to rotate rapidly, in one series of experi- 
ments in a yertical, and in the other in a horizontal direction. 
In the first case he found that the roots grew directly away 
from the centre of the Avheel, and the stems toward it — that 
is, haying in his experiment substituted centrifugal force for 
gravitation, leaving all other conditions unchanged, he found 
that the root grew in the direction of that force, and the 
stem opposite to it. In the second series of experiments, in 
Vv'hich gravitation and centrifugal force were made to act at 
right angles to each other upon the growing plantlets, the 
direction of growth coincided with that of the diagonal of 
the two forces, the roots growing diagonally outward and 
downward, the stems inward and upward. Dutrochet after- 
ward showed, by similar experiments, that many leaves are 
geotropic, turning their under surfaces toward the circum- 
ference, and their upper toward the centre of the wheel, f 

256. — If positively and negatively geotropic organs are 
placed in what may be termed their normal positions, they 
grow on the one hand downward and on the other upward, 
without any curvature, and in such case the cells in all parts 
of any section of either the ascending or descending portions 
show a symmetrical development. But if such symmetrically 
developed positively and negatively geotropic organs are af- 
terward placed in a reversed or horizontal position, they 
will become considerably curved in order to assume their 
normal positions. Thus the first roots of most young plants, 
if placed horizontally, soon become curved downward near 
their tips ; this takes place even when there is considerable 
resistance to the curvature, as is shown by the penetration 
of roots into mercury. A similar curvature in an upward 
direction, however, takes place in most stems when placed 
horizontally ; in grasses the curvature is almost entirely con- 
fined to the nodes. In such curved parts of roots and stems 
the cells are more elongated upon the convex than upon 



* "On the Direction of tlie Ra lide and Plumule during the Vegets^. 
tionof Seeds." Philosophical Transactions, ISOQ. 
+ «' Memoires," Paris, 1837. 



190 BOTANY. 

iihe concave side, and it is evident that this is the immediate 
cause of the bending. We do not, however, know how grav- 
itation causes this inequahty in the growth of the cells, 
and the problem is the more difficult from the fact that the 
more rapid elongation of the cells is in one case upon the 
upper and in the other upon the under side of the organ. 
Moreover, in ^^ weeping trees" the branches are positively, in- 
Btead of negatively, geotropic, although we know of no struc- 
tural difference between these and the branches of ordinary 
trees. 

§ V. Certain?' Movements of Plants. 

257. — ^Under this head are to be considered a few only of 
the more important movements in plants. It must be remem- 
bered that living protoplasm has everywhere, under proper 
conditions, the power of spontaneous movement. In the 
lower forms of vegetation this results in visible movements, 
which are of common occurrence ; but in the greater part 
of the vegetable kingdom, while the protoplasm is doubt- 
less as active, the cell-walls which enclose it are so rigid that 
its physical activity is incapable of j^roducing external move- 
ment. Thus most parts of ordinary plants do not perform 
movements which are the direct results of the physical activ- 
ity of the protoplasm ; bnt this is not because of a want of 
activity in the jorotoplasm, but mainly from the rigidity of 
the walls surrounding it. In a comparatively small number 
of instances, however, the structure of the organs of even 
the higher plants is such that movements directly due to pro- 
toplasmic activity are performed. Such are the so-called 
spontaneous movements of the leaves of some plants, and 
those dependent upon external stimuli, as light, heat, me- 
chanical irritation^ etc., which have been called paratonic 
movements. 

258.— Spontaneous Movements. The most remarkable 
case of movements apparently not dependent npon external 
agents is that of the leaves of Desmodium gyrans, an Indian 
plant. The small lateral leaflets of the trifoliate leaf bend 
upon their slender stalks (petiolules) in such a way that their 



MOVEMEJ^TS OF PLANTS. 197 

apices describe nearly a circle. A revolution occupies from 
two to five minutes if the temperature is above 22° Cent. 
(72° Fahr.). This continues, when the conditions are other- 
wise favorable, in darkness as well as in the light. Other less 
noticeable movements of this nature occur in many plants — 
e.g., Clover, Mimosa, Oxalis — but they are often hidden by the 
more marked movements due to other causes. The active 
portion of the moving organ (in the cases cited above, a por- 
tion of the leaf -stalk) consists of a tissue composed of thin- 
walled cells, forming, in many cases, a thickened ^' pulvinus.*' 
The cells are turgid and the tissues are in a state of tension. 
When movements occur, it appears that the protoplasm in 
certain layers of cells permits the escape into the intercellu- 
lar spaces of a portion of the water of the vacuoles ; it is, 
however, quickly absorbed again and the cells rendered 
thereby turgid, while the escape of water takes place in 
contiguous layers, to be quickly absorbed again, and so on 
regularly around the axis of the contracting organ. 

259.— Movements Dependent upon External Stimuli. 
These are exhibited by many parts of the higher plants— e.^., 
leaves in Mimosa (the Sensitive Plant), Cassia, Clover, 
Oxalis, Dionaea, etc., stamens of many Compositae, of Bar- 
berry, Portulaca, etc., stigmas of Martynia, Mimulus, etc. 
In the Sensitive Plant, the leaves, when touched roughly or 
jarred, close up quickly by the secondary leaflets moving- 
upward and forward, so that the upper surfaces of the 
pairs are approximated to each other ; next, the primary 
leaflets bend downward, and at the same time approach each 
other, and finally the whole leaf bends downward. The 
movements are in all cases at the bases of the organs, where 
tissues are developed similar to those in the spontaneously 
moving organs (paragraph 258). In the other cases essen- 
tially the same movements and mechanism are found. When 
the movements occur, there is an escape of the water of the 
vacuoles from the cells in one side of the organ, and thir 
side is, as a consequence, shortened and made concave. 
After a time the water is reabsorbed and the orsran resumes 
its normal position. In addition to the mechanical stimuli 
of jarring, concussion, etc., greater or less amounts of light. 



198 BOTANY. 

increase or decrease of temperature, and electrical discharges, 
may cause movements. Those movements which are brought 
about by changes in the amount of light constitute what are 
known as the " sleep" and " waking" of plants. Thus the 
leaves of the Sensitive Plant close up in darkness exactly as 
from a concussion, but they remain closed until the reap- 
pearance of tlie light. 

260. — The power of movement, whether spontaneous or 
paratonic, may be temporarily suspended by certain external 
conditions. Thus, according to Sachs, transitory rigidity 
or immobility takes place under the following conditions : 

1. Low Temjjerature. In Mimosa pudica rigidity com- 
mences at about 15° Cent. (59° Fahr.), in Desmodium gyrans 
at about 22° Cent. (72° Fahr.). 

2. High Temperature. Mimosa slowly becomes rigid at 
40° Cent. (104° Fahr.), and very quickly at 50° Cent. (122° 
Fahr.). 

3. Darhness, Long exposure to darkness (twenty-four 
hours or more) produces a rigidity which is only removed by 
a long exposure to light. 

4. Insufficient Moisture. When the supply of water to 
the roots of the Sensitive Plant is too little, a partial, and 
sometimes almost complete, immobility is produced, which is 
soon removed, however, by copious watering. 

5. Insufficient Supply of Oxygen. In a vacuum, or in an 
atmosphere of nitrogen, hydrogen, ammoniacal gas, etc., 
motile organs become immobile. On the other hand, in 
pure oxygen rigidity takes place also. 

6. Anmstlietics. In the vapor of ether or chloroform the 
leaves of the Sensitive Plant become immobile, but in the 
air they soon regain their motility. 

Mr. Darwin's experiments* upon the leaves of Drosera and 
Dionaea are confirmatory of the foregoing statements. The 
sensitive tentacles of the former and leaf -blades of the lat- 
ter were rendered insensible to the peculiar stimulus of con- 
tact with soluble nitrogenous bodies when subjected to most 
of the above-mentioned conditions. 



* *' Insectivorous Plants. " London, 1875. Chap. IV. , IX. , and XIII 



MOVEMENTS OF PLANTS. 199 

These facts indicate the correctness of the view that the 
movements are the results of the motility of the protoplasm. 

261.— Movements of Nutation. In the organs of many 
plants an inequality of growth is often noticeable, one side 
growing for a time more rapidly than the other. If this is 
followed by a more rapid growth upon the other side, and this 
again by a more rapid growth upon the first side, and so on, 
alternating from side to side, simple movements of nutation 
will take place, the apex of the organ swaying or oscillating 
from side to side in one plane. If the tracts of unequal 
growth pass slowly and regularly around the organ^ its apex 
will describe a circle in its nutation. 

Of simple nutation in one plane many leaves afford good 
examples ; thus in the bud the growth is greatest upon the 
outer or under side of each leaf, which, as a consequence, is 
bent upward, but in the opening of the bud the greater growth 
takes place upon the upper side. The greater growth of the 
upper side of an organ has been termed epinasty j that of the 
lower side, hyponasty. Many floral leaves exhibit first 
hyponasty and afterward epinasty, the first in the bud and 
the second in anthesis {i.e., the opening of the flower). 
Many stamens and styles exhibit nutations of this nature ; 
thus in Olaytonia both sets of organs are at first erect, but 
afterward they become divergent by epinasty. 

In many cases, particularly in leaves and the parts of 
flowers, these movements of nutation are controlled by vari- 
ous external agents, among which light and heat are the 
most important. To these are to be referred the successive 
opening and closing of many flowers, and the diurnal and 
nocturnal positions of the leaves of many plants. 

262. — Of the second class of nutations, the leaves of the 
onion, and the ends of the stems and the tendrils of climb- 
ing plants, furnish good examples. These rotate through 
circles or spirals, in the case of the hop and honeysuckle to 
the left, and in the bean and morning-glory to the right.* 

* To the right, or from left to right, is opposite to the direction of 
the hands of a watch ; to the left, or from right to left, is in the direc- 
tion of the hands of a watch. 



200 BOTANY. 

When such rotating stems come in contact with an up- 
right object they continue their rotation, and in this way 
come to twine around it. The plants mentioned above af- 
ford common examples of twining. In the case of tendrils 
nutations also occur ; but after coming in contact with any 
object there is a very unequal growth of the two sides, that 
in contact with the object growing very slowly, as compared 
with the rapidity of growth of the outer side. Thus De 
Vries found that in the tendrils of the pumpkin twined 
around an object 1.2 mm. in diameter the ratio of the 
growth of the inner side to that of the outer was as 1 to 14. 
This inequality of growth is due to a retardation of growth 
upon the inner side and an acceleration upon the outer. In 
some cases there appears to be an actual contraction of the 
inner side. 

263.— Movements of Torsion. In many cases in the 
higher plants the stems or other organs become twisted upon 
their axes. Even in the lower plants this is not uncommon — 
e.g., in Nitella, the pedicels of mosses, etc. This twisting 
appears in many cases to be due to a peculiar inequality in 
the growth of the tissues. Thus if the outer layers of cells 
grow in length more rapidly than the inner ones, the stem 
will become twisted upon its axis, and the greater the ine- 
quality in growth of the inner and outer layers, the greater 
the torsion. In some cases torsion arises in a much simpler 
way, by the twisting due to the unequal distribution of the 
weight of certain organs, as in some |)rostrate plants, where 
the weight of the leaves and the advancing and obliquely 
ascending growing extremity of the stem produce torsions 
which become permanent by the hardening of the tissues. 
Likewise torsions may arise on account of the heliotropism or 
geotropism of an organ itself, or of organs connected with it. 

It may be in place here to direct attention to tlie fact that inequali- 
ties in the growth of the tissues of plants are of common occurrence. 
They are, however, for the most part of such a nature as to prevent 
torsions of the stem, giving it, on the contrary, a rigidity which en- 
ables it to stand erect. If the pith of a growing stem of a Dicotyledon 
be isolated from the surrounding tissues, the former elongates, while 
the latter contracts, showing that the pith has grown more rapidly in 



MOVEMENTS OF PLANTS. 201 

Jengtli than the other tissues. Thus in a young internode of the Moun- 
tain Ash, 60 mm. long, the pith, when isolated, elongated 3 mm., while 
the surrounding parts shortened 1 mm. Close examination of the tissues 
fiurrounding the pith shows that they also have developed unequal- 
ly. Sachs expresses this inequality by the formula, E < C < X < P, 
which indicates that the epidermis is shorter than the cortex, the 
cortex shorter than the xylem, and the xylem shorter than the pith. It 
is at once evident that in such a condition of things the epidermis is 
elongated by the other tissues ; the cortex is shortened, on the one 
hand, by the epidermis, and elongated on the other by the xylem and 
pith ; the xylem is shortened by the cortex and epidermis, and elon- 
gated by the pith ; while the pith is shortened by the three surround- 
ingr tissues. There is thus a considerable tension in the several tissues, 
and upon this condition it may be remarked : 

1st. That it produces a rigidity of the stems or other organs in which 
it occurs. 

2d. That it tends to prevent ordinary torsion ; for the twisting of 
such a stem must elongate still more the already elongated tissues, 
while contracting the shortened ones ; on the other hand, there is some 
tendency to an internal torsion. 

3d. That the exact length of a stem is dependent upon a balancing 
of the tensions of its tissues. 

There are in many cases tensions whose directions lie at right angles 
to the foregoing. Thus in the trees of the colder climates the growth 
of new tissues from the cambium layer produces an outward pressure 
upon the bark, and an equal inward pressure upon the wood. Even in 
herbaceous plants similar tensions are often to be observed, the epider- 
mis being laterally distended by the enclosed tissues. Tensions in this 
direction, have been denominated transverse tensions, to distinguish 
them from the others, which may be called longitudinal tensions.* 

* For a full discussion of tensions the student is referred to larger 
works, such as Sachs' "Lehrbuch," and his " Experimental-Physi- 
ologie." 

The whole subject of the movements of plants, including heliotro- 
pism and geotropism, is fully treated by Mr. Darwin in his recent 
work "The Power of Movement in Plants." New York, 1881. 



PART II. 

SPECIAL ANATOMY AND PHYSIOLOGY OF PLANTS, 
AND OUTLINES OF THEIR CLASSIFICATION. 



CHAPTER XIII. 

CLASSIFICATION. 

264. — In order to obtain a definite knowledge of the com- 
parative structure of plants, it is necessary here to take up 
in order the different groups, and to study with some care 
the more important modifications and differences noticeable 
in the plant-body. This study, so taken up, is intimately 
connected with the classification of plants ; the differences 
and modifications of structure which we study in order to 
gain a better knowledge of plants as a whole, are the very 
ones which serve to separate the vegetable kingdom into 
larger or smaller groups. This part (Part II.) of this trea- 
tise will, therefore, include the outlines of the Classification 
of Plants, as well as a discussion of Special Morphology. 

265. — (1.) In the classification of living objects they ^^are 
arranged according to the totality of their morphological re- 
semblances, and the features which are taken as the marks 
of groups are those which have been ascertained by observa- 
tion to be the indications of many likenesses or unlikenesses. "* 
Such an arrangement is " a statement of the marks of sim- 
ilarity of organization, and of the kinds of structure which, 
as a matter of experience, are universally found associated 
together." 

* T. H. Huxley in tlie article "Biology," in " Encyclopeedia Britan- 
nica." ninth edition, Vol. III., p. 688. 



classification: 203 

266. — (2.) Every natural classification takes into consider- 
ation not only the adult characters, but also those of the 
embryonic life of its objects. It is not enough to know the 
differences and resemblances between two plants in their 
adult state ; we must also know whether they differed or not 
in their modes of reaching that state. In other words, in 
order to determine the degree of relationship existing be- 
tween two or more plants, all the characters of each plant, 
as presented in its whole life, must be taken into the ac- 
count. By ignoring this important law great confusion has 
arisen, especially in the lower groups of plants. 

267. — (3.) There is still another factor which should 
enter into classification. Every classification should show 
real relationship, not similarity alone ; it should bring to- 
gether not those which sim23ly show present coincidences, 
but those in which similarity of form indicates similarity 
of origin ; in addition to structural relationship, it should 
show genetic relationship. This can be accomplished only 
by a study of the genealogy of plants, a subject surrounded 
by many difficulties. In but few cases can we trace an 
ancestral line, and yet it is desirable that we should use the 
facts we have, as by so doing we shall be the more likely to 
discover others. 

{a) It is a mistaken notion that living things can be grouped natu- 
rally by taking into consideration only one, or even two or three char- 
acters. Botany and zoology are full of the debris of attempts at classi- 
fications upon single characters, and in every case such classifications 
have proved a hindrance to knowledge. The division of the vegetable 
kingdom into Flowering and Flowerless Plants, by Ray,* in 1703, is an 
illustration of one based upon a single character. The influence of 
this classification, which is even yet much followed, has been injurious. 
It has kept alive the notion that the so-called Flowerless plants are 
quite different as to their reproductive organs from the Flowering ones; 
it fixed an imaginary gulf between groups of plants, some at least of 
which are in nature placed side by side. Endlicher'sf two great 
groups, Cormophyta and Thallophyta,are likewise based upon a single 
character, and are, as a consequence, misleading. The Thallophytes are 

* John Ray : " Methodus Plantarum emendata et aucta." 
f Stephen Endlicher : " Genera Plantarum secundum Ordines Natu- 
rales disposita." 1886-40. 



204 BOTANY. 

not all tliallus plants, nor are all tlie tliallus plants found in the Thal- 
lopliyta ; on the other hand, the Cormophytes are not all plants with 
trunks or stems. 

(6) We often, however, retain in our present classification some of 
the groups founded originally in this erroneous way, and even some- 
times retain their old names. For example, the group Phanerogamia 
includes now the same plants it did when its exceedingly inapplicable 
name (Phanerogamia, from (pavepo'i, open to sight, and ■ya/j.o'i, marriage) 
was applied to it ; but it now rests upon a more scientific basis. The 
name is now unmeaning, and refers to no character or set of characters 
now used to designate the group ; and, more than this, its etymological 
signification is actually directly opposite to the facts as now known. 
The term Cryptogamia {KpvTrTog, hidden, and yd/xog, marriage) no longer 
exists in a scientific sense, as it is no longer the name of a group of 
plants ; not only has the term now no meaning (for the plants it refers 
to have a fertilization which is far less " hidden " than in the so-called 
Phanerogams), but the plants it formerly designated by a negative 
character are now known by positive characters to belong to several 
groups. We may still use the word Cryptogam in speaking of the 
'members of certain groups of plants, just as in zoology we frequently 
make use of the word Invertebrate ; but in neither case are the terms 
the names of natural groups, or of natural assemblages of groups. It 
is convenient to retain them as popular names of certain artificial as • 
semblages of groups. 

(c) The term Thallophyta is to be placed in the same category. It is 
still used to designate a great assemblage of the lower plants, but the 
original meaning of the term is lost, and the limits of the group to 
which it was applied have been somewhat changed, while the plants 
composing it have undergone an entirely new distribution into new 
groups. Nevertheless, it is convenient to retain the term, although in 
this, as in the previous cases, care must be taken not to suppose that 
when used it designates more than an artificial assemblage of natural 
groups of plants. 

(d) The importance of the study of the individual development of 
plants can hardly be overestimated. What Embryology has done for 
zoological. It doubtless can do for botanical classification. It is already 
bearing fruit ; the recent advances in the classification of the algse and 
fungi are due to a study of the whole life of the individual. In the 
fungi the long list of spurious families and genera, and the yet longer 
one of spurious species, bear witness against the system of classification 
under which they came into existence. 

(e) There is another reason for studying closely the life-history of the 
individual, which is that it throws some light upon the difficult ques- 
tions relating to the ancestry of plants. The life-history of the indi- 
vidual appears to bear much resemblance to the life-history of the 
species ; and while no doubt it would be unsafe in any particular case 



CLASSIFICA TION, 



205 



to assume that the specific development had followed lines parallel to 
those of the individual, yet the latter may always serve to point out the 
probable course of the former. 

268. — Applying the preceding principles, so far as possi- 
ble, we find that the yegetable kingdom may be quite readily 
separated into six principal Divisions, which, although by no 
means distinct, are capable of being quite clearly character- 
ized. To these must be added a seventh, composed mainly 
of unclassified and poorly understood forms. These seven 
Divisions, beginning with the lowest, are, (1) Protophyta, 
(2) Zygophyta, (3) Oophyta, (4) Oarpophyta, (5) Bryophy- 
ta, (6) Pteridophyta, (7) Phanerogamia, or Anthophyta. ^ 

Their relation to the old groups Oryptogamia, Thallophy- 
ta, etc., may be seen from the following tabular comparison : 



I. 

Ray, 1703; Linnaeus, 1735. 



Flowerless (Ray), 
Cryptogamia (Lin- 
naeus). 

Flowering (Ray), j 
Phanerogamia(Linn.) j 



II. 

De Candolle, 
1813. 


III. 
Endlicher, 
1836-40. 
r 


Cellular 
Plants. 


Thallophyta. 






Vase u 1 a r 
Plants. 1 


Cormophyta. 








IV, 

1. Protophyta. 

2. Zygophyta. 

3. Oophyta. 

4. Carpophyta. 

5. Bryophyta. 

(j. Pteridophyta. 

7. Phanerogamia. 



The arrangement in the fourth column, which will be fol- 
lowed in this book, is essentially that of Sachs, with some 
modifications,, which will be pointed out hereafter. 

It is only necessary in this place to say that the classification here 
given does not recognize the old groups Algm and Fungi. The terms 
are, however, quite useful, if properly used and understood, and con- 
sequently they will be retained when general reference is made to the 
chlorophyll-bearing and the chlorophyll-free Thallophytes. By the 
term alga must be understood a ThallopLyte wliicli contains chloro- 
phyll ; and by fungus one which is saprophytic or parasitic in habit, 
and which is, as a consequence, destitute of chlorophyll. The terms 
have thus, as here used, a physiological meaning only, and not a class- 
ificatory one. 



CHAPTER XIV. 

THE PROTOPHYTA. 

269. — The Protophytes are the lowest and simplest plants. 
In many cases they are exceedingly minute, requiring the 
highest powers of the microscope for their study. For the 
most part the cells are poorly developed ; the protoplasm 
is frequently destitute of granular contents ; the nucleus is 
wanting in many cases, and not infrequently there is either 
no cell-wall, or only a poorly deyeloped one. The cells in 
all cases have little or no coherence, and even when they are 
united into loose masses, each cell retains nearly as much 
independence as in the unicellular forms. The differentia- 
tion of cell-form is very slight, even in those cases where 
there is the greatest coherence of cells, and yet in some or- 
ders certain cells of the filaments are uniformly larger than 
the others, as the ^Hieterocysts" of Nostoc, and the ^^ basal 
cells " of the filaments of Rivularia. 

270. — No sexual organs are known, and whether the sex- 
ual act occurs or not is somewhat doubtful. As, however, 
we must not expect to find well-developed organs or as 
distinct a sexual act in these simple organisms as in more 
complex ones, it is possible that both exist in the group, 
but have hitherto been overlooked or misunderstood. 

Their most common mode of reproduction is by fission, 
and in only a few cases by internal cell-division. 

271. — The lowest Protophytes are destitute of chlorophyll, 
or any other coloring-matter, and in those orders in which 
chlorophyll occurs it is usually associated with a blue or red 
pigment. 

Many Protophytes exist in masses of a considerable size, 
composed of large numbers of individuals imbedded in a 



MTXOMYCETES. 207 

gelatinous matter, wliich appears to be formed by a partial 
degradation of the walls of the cells. They are mostly 
aquatic ; and the species which are terrestrial live in damp 
and generally shaded places. 

§ I. Class Myxomycetes. The Slime Moulds. 

272. — In this class is included a large group of remark- 
able organisms, which differ in many respects from all other 
vegetable structures. In many of their characters, as in 
having no cell-wall during the period of their active growtl^^, 
in being destitute of a nucleus, in their mode of nutrition, 
and in the motility of their naked protoplasm, they resemble 
certain Monera among the Protozoa ; * while, on the other 
hand, they have a close external resemblance to certain 
higher fungi (puff-balls and their allies). 

273. — It is difficult to give the Myxomycetes a satisfac 
tory place in the vegetable kingdom. They have no struc- 
tural affinities with plants higher than they are, nor with 
any lower ; they stand alone, and appear to belong to a dif- 
ferent genetic line. So, although taken up here, they must 
not be regarded as on that account the lowest or the first of 
the Protophytes. 

274. — All members of this class agree in being composed 
during the vegetative portion of their existence of naked 
masses of protoplasm (Fig. 140), which are yellow, brown, 
purple, etc., but never green. These j^/a^mot^m, as they are 
called, are, during the period of their active growth, endowed 

* There are fewer reasons now than forraerly against regarding these 
as near relatives of tbe Monera. We no longer imagine an absolute 
line of separation between the lower portions of the great domain of 
life, and hence may now admit relationships which formerly were in- 
admissible. It is by no means an improbable hypothesis that in the 
Myxomycetes we have the terrestrial phase and in the Monera the 
aqnatic phase of a common group of organisms. The Myxomycetes are 
not Monera, but they are Moneran in their structure, and probably also 
in their affinities. All the differences between the Myxomycetes and a. 
Moner like Protomyxa, for example, are probably referable to the 
'•errestrial habit of the former as contrasted with the aquatic habit of 
the latfp". 



208 



BOTANY. 



with a remarkable motility, enabling them not only to 
change their form, but their place also. When the proto- 
plasm passes into a condition of rest, it forms itself into 
small rounded masses, each of which secretes a covering of 
cellulose about itself. This resting condition may be brought 
about in two ways : first, through unfavorable conditions, 
as the absence of the requisite amount of moisture ; in such 




Fig. 140.— Plasmodium of Ph/ysarum leuwpus {Didymium leucopus of Link), st^ 
the more granalar central part of the threads, x 350.— After Sachs. 

case the masses formed are larger, and irregular in size, and 
constitute the so-called sderotiiim stage ; upon the return of 
the proper conditions the sclerotia return to the soft and 
motile condition of the original plasmodium ; the second 
mode of formation of the resting stage takes place only 
when the plasmodium has apparently concluded its period 
of vegetation ; the protoplasm becomes heaped up in a com- 
pact or even elevated mass, which then separates internally 



MTX0MYCETE8. 



209 



into a large number of minute rounded bodies, the spores, 
each of which is provided with a cell-wall. This latter is 
called the spore-bearing stage, or simply the fructification of 
the organisms. 

275. — When placed under proper conditions of moisture 





Fig. lAl.—Fuligo varians {^ihalium septicum of Fr.). a spore; b, c, spore-case 
rupturing and permitting the protoplasmic contents to escape; of, rounded mass of 
naked protoplasm escaped from the spore-case; e, f, ciliated swai'm-spore or 
zoospore stage; g, h, i, k, I, amoeba stage; m, young Plasmodium.— After Prantl. 

and temperature, the spores burst their walls, and the im- 
prisoned protoplasm in each escapes and soon becomes a 
motile, nucleated mass, provided with 
a cilium, or having an amoeboid form ; 
in this stage (called the swarm-spore) 
it repeatedly divides by simple fission 
(Fig. 142). After a day or two, the 
swarm-spores, now destitute of ciUa, 
begin the reverse process of coales- 
cing, two or more of them fusing into 

a common mass; the process may Ife^X^^.d^rgoinf Son' 
continue until a new plasmodium is x 39o.— After De Bary. 
formed, differing from the first one mentioned only in size 
(Fig. 141, a to m, and Fig. 143). (See Note on page 49.) 

276. — The classification of the Myxomycetes is mainly 
based upon the fructification, which usually consists of a 




Fig. 142.— Swarm-spores of 
Chondrioderma d iffo r m e 



210 



BOTANY, 



sporangium, wliicli may be distinct (Fig. 144, B), or it may 
be a flattish, cake-like mass, the so-called mtlialium, directly 
derived from the plasmodium. In most cases the spore- 
bearing masses contain internally, besides the spores, a 
structure called the CapiTlUium, consist- 
ing of thin-walled, spirally thickened, or 
otherwise marked tubes variously disposed 
(Fig. 144, C, cp). In some cases, where 
there is a distinct sporangium, the pedi- 
cel of the latter is continued into it as a 
central column ; this is known as the Col- 
U7nella; it may send out branches which 
support the walls of the sporangium. 




Fig. 143. — Swarm- 
Bpores of Chondrioder- 
ma difforme {Didy- 
mivrn Libertiamim of 
De Bary) coalescing or 
conjugating, x 390. — 
After Cienkoweki. 



{a) The following classification of the Myxomy- 
cetes is by Rostafinski.* He distinguishes seven 
orders : 

Order I. Protodermese. Sporangia simple, of regular shape, not 
possessed of a capillitium, with violet spores. 

Order II. Calcareee. Sporangia simple or compound, often pro- 
vided with a columella, spores violet or violet brown ; whole fructifica- 
tion, with more or less de- 
posits of carbonate of lime. 

This includes many com- 
mon species, under the 
genera Physarum, FuUgo, 
Didymium, 8pumaria, etc. 

Order III. Amauro- 
chaetese. Single sporan- 
gium or sethalium, with- 
out lime ; spores, capilli- 
tium, and columella almost 
always uniformly black, or 
brownish-violet colored. 

In this order the genus 
Stemonitis furnishes the 
most common species. 

Order IV. Anemese. 
Sporanjrium or aetlialium 
without capillitium or lime; columella not evident, wall of sporan- 

* " Sluzowce Monografia" by Joseph Rostafinski, 1875. Zopf (" Die 
Pilzthiere," 1884) extended the class so as to include many genera, e.g., 
Vamp3^rella, Protomonas, Protomyxa, Plasmodiophora, etc., which 




Fig. 144.— Fructification of Arcyria incaraata 
{A. adnata of Rtfki.). B, young sporangium; (7, 
mature sporangium ruptured ; ep, capillitium; 
p^ wall of sporangium, x 20. — After Sachs. 



SCHIZOMTCETES. 211 

gium without net-like tliickeuings, now and tlien symmetrically per- 
forated. 

Licea and Tuhulina are genera of this order of which we have 
species. 

Order V. Heterodermese. Sporangia without capillitium, colu- 
mella, or lime ; wall of sporangium delicate, when mature at least partly 
cracked, exposing the net-like flat thickenings of the inner side of wall ; 
spores and thickenings of the inner wall in one and the same sporan- 
gium usually of uniform color. 

Dictydium and Grihraria are our common genera. 

Order VI. Columelliferse. Spores, capillitium, and columella 
uniformly bright-colored, without lime ; capillitium of very thin-sided 
tubes, without thickenings, combined into a thickly intricate but loose- 
hanging net. 

Represented by the genus Reticularia. 

Order VII. Calonemeae. Walls of sporangia, spores, and capillitium 
usually uniformly colored in the same sporangium. Color variable 
from yellow to brownish or chestnut ; more rarely olive green or gray- 
ish white ; capillitium usually strongly developed ; threads simple, or 
combined into a net, either entirely free or grown to certain places of 
the wall of the sporangium ; walls of the threads very rarely smooth, 
usually provided externally with protruding thickenings, either spiral- 
shaped or under the form of numerous spines, warts, or transverse 
rings ; without fixed columella ; exceptionally containing lime, exclu- 
sively on the walls of the sporangia ; now and then sethalia covered 
with a stout double cortex of colored cells. 

Arcyria and Trichia are our common genera. 

(&) Specimens of the Slime Moulds may be obtained for study by ex- 
amining the surfaces of decayed logs, and the bark-covered ground in 
tan-yards. They may frequently be found on decaying leaves, and 
occasionally on the grass and mosses near decaying vegetable matter. 



§ II. Class Schizomycetes. 

277. — These are minute unicellular Protophytes, which 
reproduce mainly by transverse fission. The cells are gener- 
ally somewhat elongated, often much so, although in one 
family they are spherical ; they are sometimes provided with 
cilia, by means of which they move rapidly through the 

are commonly placed in the Animal Kingdom. Zopf's system is fol- 
lowed by Berlese in Saccardo's " Sylloge Fungorum." vol. vii., 1888, 
in which all the known species in the world (about 450) are described. 



312 BOTANY. 

water. They occur in solutions of organic matter in im- 
mense numbers, and are said even to appear in solutions of 
inorganic salts under proper conditions.* 

278.— Order Bacteriacese. This includes the organisms 
known as Bacteria, and which are present in fermenting and 
putrefying matter ; they also occur in the blood and the air- 
passages of diseased animals, and the tissues of some dis- 
eased plants, where they have been shown to be the cause of 
many kinds of disease. Cohn f defined Bacteria as '' chlor- 
ophyll-less cells of spherical, oblong, or cylindrical form, 
sometimes twisted or bent, which multiply themselves ex- 
clusively by transverse division, and occur either isolated or 
in cell-families. '' Many forms have since been shown to 
produce spores, and these are most important agents in their 
multiplication and reproduction. In the unicellular Bac- 
teria the cells resulting from division separate at once, while 
in the filamentous forms they remain in connection, forming 
elongated strings or threads. Bacteria sometimes form a 
jelly-like mass by the swelling up of their cell membranes; 
this is the Zooglma stage. When they have exhausted the 
nutriment from the liquid, they form a pulverulent precipi- 
tate, which may be regarded as a resting state. '' Most 
Bacteria present a motile and a motionless condition; the 
former is connected with the presence of oxygen." 

It is now known that many Bacteria pass through various 
stages, e.g.. Coccus, Bacillus, Vibrio, etc., which were for a 
time supposed to be generic forms, under which species were 
described, as was done by Cohn. The real limits of genera 
and species cannot in the present state of our knowledge of 
these organisms be determined. We may, for the present, 
make use of Cohn's system, remembering that it is merely 
a classification of observed forms. 

* See Bastian's " Beorinning-s of Life," Vol. II., Appendix. 

f "Researches on Bacteria" (Untersucli. liber Bacterien) in " Beitrag© 
zur Biologie der Pflanzen," Breslau, 1872, See a resume of this paper 
in Quarterly Journrd of Microscopical Science, 1873, p. 156. See also 
English accounts of further researches by Cohn, 1875, 1876; in the 
journal just cited, 1876. p. 259. and 1877, p. 81. Consult " The Bac- 
teria," by Dr. A. Magnin ; translated by Dr. Sternberg. Boston, 1880. 



SCHIZ0MYCETE8. 



313 



{a) Colin separated Bacteria into four tribes, as follows . 

(1) Splicer ohacteria, with spherical cells. The only genus is Micrococ- 
fus. The species M. crepusculum, M. candidus, and M. urem produce 
certain kinds of fermentation ; the color-producing species are M. pro- 
digiosus {a, Fig. 145), which causes the blood-like patches on bread, 
flour, paste, etc., M. luteus, M. aurantiacus, M. chlorinus, M. cyaneus^ 
^nd M. violaceus ; those producing or accompanying diseases are if, 
inccincB, M. dipMhericus, M. septieus, and M. bombycis. This latter 
group is of great importance, but it is one the investigation of which 
presents unusual difficulties. Oth- 
er species than those named are 
supposed to exist. 

(2) Microbacteria, with very 
small cylindrical cells. The only 
genus is Bact&i'ium. The species 
are, B. Termo (b, Fig. 145), the 
common agent of putrefaction ; 
B. lineola (c. Fig. 145), a larger 
species found in brooks and 
ponds ; B. xanthinum and B. syn- 
cyanum, which are color-produc- 
ing; and B. ceruginosum, which 
is found in blue-green pus. 

(3) Desmobacteria, with filiform 
cells. There are two genera, Ba- 
cillus, with the filament straight, 
and Vibrio, with the filament curv- 
ed or undulated. Of the first there 
are three species, viz.: B. subtilis, 
which ia the butyric ferment ; B. 
ulna {d, Fig. 145), much like the 
preceding, but larger ; and B. 
anthracis, which is the cause or 
accompaniment of the diseases 
known as anthrax and "ma- 
lignant pustule." Vibrio has two 
species, viz. : V. Rugula (e, Fig. 145), whose cells are thick and rather 
phort ; and V. serpens, whose cells are of smaller diameter, but of 
greater length than the preceding. 

(4) Spirobacteria, with spirally twisted cells. There are two genera, 
SpirocTicete, with a much twisted spiral ; and Spirillum, with a less 
twisted spiral. Of the first the single species is Sp. plicatilis (/, Fio". 
145), and of the second, Sp. teiiue, Sp. andula and Sp, wlutans (g. 
Fig 145), the latter a gigantic species, with a flagellum at each end 
of the spiral. 

(&) Bacteria may be readily procured for study by infusing a pinch 





jy^:} 



Fig. 145. a, Micrococcus prodigiosus^ 
(Monas prodigiosus of Ehrenberg) ; b, 
Bacterimn Termo, zoogloea stage ; c. Bac- 
terium lineola ; d. Bacillus ulna ; e. Vi- 
brio Rugula; f, Spirochcete plicatilis ; g. 
Spirillum vohitans. x 650.— After Cohii. 



214 BOTANY. 

of cut hay or any other similar vegetable substance in warm water for 
an hour, and then filterinfr ; the filtrate will, if kept at the ordinary 
temperature of a room (20° C), and allowed free access of air, become 
turbid with Bacteria in the course of one or two days. 

(c) By adding a drop of the hay infusion to Pasteur's solution,* made 
without sugar, the previously clear liquid is soon made turbid by the 
rapid increase of Bacteria.f 

279^ — Here liave usually been placed the species of Sac- 
char omyces which produce fermentation in sugar solutions. 
The type of the genus is Saccharomyces cerevisice, the yeast 
plant (Fig. 14G). It presents two conditions : in the first it 
is in the form of transparent round or oval cells, averaging 
.008 mm. (.0003 inch) in diameter; these reproduce by bud- 
ding (a modification of fission), a small daughter-cell being 

formed by the side of the 
mother-cell, and sooner or later 
separating from it (Fig. 146, a, 
h). The other form consists of 
larger cells, which, by a division 
of their protoplasm, form four 
new cells within the parent-cell 
mg. i46.-The Yeast v]^nt Saccha- (Fi^. 146, c, cl). This has com- 

romyces cerevisice. a. rounded cells v o j j j 

from " bottom yeast," 50 hours after monlvbeen res^arded as no more 

sowing in beer-wort; &, row of oval "^, ... 

cells from "top yeast ;" c, " bottom than internal cell-divisiou, but 

yeast" after cultivation on a piece of ... n j^i i • 

carrot, four cells forming in the inte- it IS UOW generally tnOUgJlt 

rior of the parent cell; d, the four i. r -» o-voafor- iTnnnvtQTi r^a t 

daughter-cells, a and &X 400, c and (« tO be Ot gieatCI mipOltanCC.]; 

X ?5o.-After Reess. rj.j^-g formation of ucw cells by 

internal cell-division appears to occur only when the supply 
of nourishment is less abundant, as Avhen the yeast is grown 
on cut slices of potato or carrot. 

* Made as follows : Potassium phosphate, 20 parts ; ciilcium phos- 
phate, 2 parts ; magnesium sulphate, 2 parts ; ammonium tartrate, 
100 parts ; cane sugar, 1500 parts ; water, 8376 parts. The sugar is 
to be omitted in some cases. 

f The student may profitably refer to Huxley and Martin's "Ele- 
mentary Biology," Chap. IV., for directions in making his observations. 

X Reess, in his " Botanische Untersuchungen liber die Alcohol gah- 
rungspilze," 1870, calls this process the formation of ascospores, the 
mother-cell he calls an ascus, and the daughter-cells true ascospores. 
Accor lingly he considers these plants to be very simple Ascomycetes ! 




CTANQPHYGEJSl. 215 

280. — It was formerly held that the yeast plant was only 
the immature condition of a mould;* but Brefeld's re- 
searches,! which were undertaken to determine whether 
true yeast ever develops into a filamentous form, seemed to 
be decisive against that view. Recently, however, there has 
been a return to the former view, and botanists are now 
pretty generally agreed that Yeast Plants are greatly de- 
graded Ascomycetes (p. 323). 

{a) Examinations of tlie yeast plant are easily made by placing a 
very small drop of active yeast upon a glass slide, and, after covering 
it in the usual way, keeping it. in a warm and moist chamber for some 
hours, at the end of which time the "budding" will have become 
quite well marked. A slide so prepared may be examined immedi- 
ately, but with less satisfactory results. 

(&) Yeast may be grown in abundance by placing a few drops in a 
quantity of Pasteur's solution, in which it grows with great rapidity 
in a temperature of 30° to 35° C. (about 90° Falir.). 

(c) The state in which daughter-cells are formed may be developed 
by growing the yeast-cells (those called bottom yeast are the most sat- 
isfactory) upon fresh-cut slices of potato, kohl-rabi, carrot, or, better 
still, upon small slabs of plaster of Paris. The preparations must be 
kept moist by covering with a bell-jar ; with proper care the formation 
of daughter-cells will be seen in a week or ten days from the begin- 
ning of the experiment. 

{d) In order that the study of these organisms may be at all satisfac- 
tory the student should be provided with high powers of the micro- 
scope, say from 600 to 800 diameters.:}: 

§ III. Class Oyaitophtce^. 

281. — These are blue-green, verdigris-green, brownish 
green, or rarely purple or red Protophytes, which, in addi- 
„tion to chlorophyll, contain a soluble coloring-matter — ■ 



* "Yeast is, in fact, nothing more than a peculiar condition of a 
species of PenicilUum, which is capable of almost endless propagation 
without ever bearing perfect fruit." Berkeley's " Introduction to Cryp- 
togamic Botany," 1857, p. 299. 

f In Flora, 1873. 

X The student is again referred to Huxley and Martin's " Elemen- 
tary Biology ;" in Chap. I. will be found a valuable account of the 
yeast plant, with directions for making examinations. 



216 



BOTANY. 



I 



plnjcocyajiine — and a less soluble oi\Q~—pliycoxanthi7ie.* 
Structurally the members of this class differ but little from 
the Schizomycetes, although they are of a much larger size. 
The cells generally show a little more coherence than in the 
last class. 

They live in fresh or stagnant water, or upon damp 
gj ound, rocks, or decaying wood. Unlike the Schizomycetes, 
they do not normally inhabit putrid solutions. 

282.— Order Chroococcacese. This is made up of uni- 
cellular plants. The cells, which are spherical, oblong, cylin- 
drical, or angular, are either single, or more commonly united 
by a common jelly into families. Cell-division (in reality 
internal cell-division) takes place in 
either one, two, or three planes (Fig. 
147). 

Thirteen genera are known in the United 
States :, (1) Chroococcus, with globose, oval, 
or angular (from pressure) cells, which are 
solitary or in free families; our four species 
grow on wet rocks or in springs; (2) 
Olceocapsa (Fig. 147), with spherical cells, 
which are solitary or in enclosed families j 
our eleven species form a firm grumous or 
gelatinous coating of a light brown color 
on wet rocks ; (3) ClodospJiceritim, with very 
small cells, forming a thallus-like mass; we 
have one species, forming a light-colored 
scLim on stagnant water ; (4) Merismopedia, 
with globose, oval, or oblong cells, which occur in tabular families of 
four, eight, sixteen, etc. ; our two species inhabit streams and fresh 
ponds. Clatlirocysiis, Anacystis, etc., are common. . 

283.— Order Nostocacese. The plants of this order are 

* Phycocyanine, the blue coloring-matter, is extracted from the 
crushed plants by cold water ; the solution is blue by transmitted and 
blood-red by reflected light. After the extraction of phycocyanine, 
treatment of the crushed plants witli strong alcohol produces a green 
solution which contains chlorophyll, and a yellow coloring-matter, 
phycoxanthine ; the latter may be separated by shaking up with the 
green solution a large quantity of benzine, which takes up the chloro- 
phyll, and when at rest rises and forms a green upper layer containing 
chlorophyll, below which is the yellow alcoholic solution of phycoxan- 
thine. 




Fig. lA'^.—Gl(WGapsa in dif- 
ferent stages of growth, show- 
ing mode of cell-multiplica- 
tion. The daughter cells are 
surrounded by the gelatinous 
walls of the mother-cells. A, 
youngest ; E, oldest stage. 
X 300.— After Sachs. 



CYANOPHTGE^K 217 

composed of rounded cells loosely united into a filament and 
generally imbedded in jelly (Fig. 148, A) ; tliey frequently 
form large masses, united by tlie glutinous jelly. At inter- 
vals in the filaments tliere are larger clear cells — the hetero- 
cysts — which appear from analogy to be reproductive bodies, 
although nothing is positively known as to their function. 
The usual mode of reproduction is by the simple fission of 
the cells. I^ew masses or colonies are formed by the break- 
ing up of the old filaments into pieces composed of a few 
cells, which then become endowed with a power of motion 
which consists of a slow bending from side to side with a 
forward movement at the same time. Each moving fila- 
ment, when it comes to rest, may become the centre of a 
new colony, which arises from it by fission. 

Six genera and thirty or more species are known in the United 
States. The principal genus 
is Nostoc (Fig. 148, A)-, its ^ 

species form jelly-like masses 
from the size of a pin-head to 

several inches in diameter in ^^ ^ 

ponds and streams, adhering ^feyddfelayals¥lsfcteiej^|p ii|^ife|#j;g|^^i^^ 
to sticks and twigs, and on wet Y\g. 148.—^, a filament of a Nosioc, with a 
ropk^ or wet e-round • thev ^^^S^ heterocyst ; B, end of filament of 6*5- 
rocKS oi wei gi"Li"^> <^i^«.y ciUatoria. x 300. -After Prantl. 
even grow mside oi other 

plants — e.g., Anthoceros Icevis — and, according to the present view, con- 
stitute the so-called gonidia of certain lichens, 

284.— Order Oscillatoriacege. The filaments in this or- 
der are composed of more closely cohering cells than in the 
previous one ; the cells unite by broad surfaces to form a 
rigid, cylindrical, straight or slightly curved filament (Fig. 
148, B). They form dark-green, loose, or felted masses in 
water or on wet earth, and are remarkable for the peculiar 
oscillating movements of their filaments. No other method 
of reproduction than by fission is known. 

The principal genus is Osdllaria, of which we have about thirty 
species. 

285.— Order Bivulariaoese. The filaments in this order 
present a greater differentiation than in any of the preced- 
ing ; they are usually arrano-ed in a radiating manner, and 
imbedded in a common jelly, so as to form small rounded 



218 BOTANY. I 

masses. Eacli filament lias a basal cell (which is spherical 
and thick walled), and sometimes interstitial ones ; the prin^ 
cipal cells of the filaments are usually cylindrical and often 
much elongated ; at the outer end they become attenuated 
into long slender hyaline hairs. Special reproductive bod- 
ies, called resting spores, are formed before the close of the 
growing season ; these appear just above the basal cells, one 
on each filament, and are much larger and thicker walled 
than the remaining cells. Upon the death of the mass of 
filaments the resting spores remain, and from these upon the 
advent of favorable conditions new filaments are developed. 

Five genera are known in the United States, the principal ones 
being Rivularia, Calothrix, and Mastigonema ; their species are found 
in water or wet places everywhere ; they also constitute the so-called 
gonidia of lichens. 

286.— Order Scytonemaeese. In this order the differen- 
tiation becomes so great that the filaments may be said to 
attain a distinct individuality ; they branch here and there, 
and are furnished with thick-walled heterocysts, which are 
basal or interstitial. In this order there is also a well-de- 
veloped sheath surrounding each filament, which may be 
compared with the poorly defined one of the preceding 
orders. The filaments form little masses or mats, growing 
in the water or on wet ground, or even on the moist bark of 
trees. 

We have five genera, the principal one of which is Scytonemay 
which contains nineteen species. Some of these are the "gonidia" 
of lichens. 

287 o — Closely related to the foregoing is the doubtful 
order Palmellaceas, now generally said to belong to the next 
Branch (p. 231). The cells are single or in colonies, and im- 
bedded in a gelatinous matter, much as in the Chroococcacese; 
but the cells are destitute of phycocyanine or phycoxanthine, 
containing only chlorophyll. This, however, is hardly a 
sufiicient character for separating them. It is, moreover, 
not certainly known whether the forms included in t?iis 
order are autonomous species; it seems probable that at 
least a portion of them are only early stages of other plants. 



CYANOPRYCE^^. 



219 



288. — The genera Protococcus, Chlorococciom, and one or 
two others, are probably to be placed near the Palmellacese, 
although their autonomy is doubtful also. They are all 
unicellular in the strictest sense of the term, and reproduce 
mainly by fission. In their resting stage they are spheroidal ; 
in their motile stage they are provided with two cilia. The 
latter form is said to arise from the former by internal cell- 
diyision, which results in the production of '^gonidia"of 
two sizes, the larger being termed macrogonidia, and the 
smaller microgonidia. 

These organisms are common in shallow pools, in the gut- 
ters of roofs, and on the wet earth. 

{a) For an account of the structure of Protococcus, with directions 
as to methods of study, see Arthur, Barnes and Coulter's "Hand- 
book of Plant Dissection," p. 22, 

{h) In the study of the Cyanophycese, and of other "fresh-water 
algfe," the student will find Rev. Francis Wolle's "Fresh-water 
Algse of the United States" (1887) of great value. 

(c) On account of their ready perishability, Protophytes are scarcely 
found in a fossil state. Schimper records a species of Nostoe from the 
Tertiary. 

((?) The relationship of the classes of the Protophytes may be indi- 
cated by the following diagram : 



Arkangement of the Classes op Protophyta. 

Cyanophyceaa 



Myxomycetes. 



Schizomycetes. 



.?-.?..?. 



CHAPTER XV. 

ZYGOPHYTA. 

289.— This is an assemblage of quite simple plants, none 
of its members attaining any great degree of complexity. 
For tlie most part the plant-body consists of an elongated 
filament composed of united cells ; sometimes, however, 
they form surfaces, and in other cases the plants are unicell- 
ular, or aggregated into communities. In these plants we 
find the first examples of undoubted sexuality, and through- 
out the group, the organs and methods of fertilization are 
nearly enough uniform to enable us to use them as distin- 
guishing characters. The sexual organs all have this in com- 
mon, that between the male and the female there is no ap- 
preciable difference as to form, size (with a few exceptions), 
color, origin, etc. In the sexual processes, likewise, there is 
this in common, that the result of the union of the two 
sexual cells is the production of a new cell, the zygospore, 
possessing very different characteristics from either. While 
the sexual cells have only ordinary walls, or none at all, the 
zygospores are covered with thick, firm walls. 

290. — The zygospore is frequently called the '^resting 
spore," because under certain circumstances it remains quies- 
cent, while retaining its vitality, often for long joeriods of 
time. Thus at the close of the growing season, as upon 
the advent of the summer drought, or of winter, the zygo- 
spores fall to the bottom of the pools (in the aquatic forms), 
and in the dried or frozen mud remain uninjured uutil the 
return of favorable conditions, when they germinate and give 
rise to a new^ generation of plants. 

291. — Nearly all the plants of tliis groujD contain chloro- 
phyll, only one order being destitute of it. The green forms 
are all aquatic, and inhabit either fresh or salt water. They 



ZOOSPORES. 221 

include the greater part of tlie green algae of our ponds 
and streams. Those which have no chlorophyll are sapro- 
phytes, and live upon dead organic matter. They are doubt- 
less to be regarded as modified forms of some of the types 
of the chlorophyll-bearing portion of the group. 

§ I. Class Zoospores. 

292. — This class is a somewhat doubtful one ; it is com- 
posed of plants which, while differing in many other re- 
spects, agree in having locomotive sexual cells {zoospores). 
In this they agree, however, with the VolvocinecB, and bear 
a close resemblance to Frotococcus and its allies. It is prob- 
able that a fuller knowledge of some of the plants of this 
class will result in their being distributed elsewhere. 

The general structure of the plants referred to this class 
may be understood from the examples which follow. N"o at- 
tempt will be made here to indicate the orders to which 
they belong. 

293. — Pandorina is a unicellular alga, wdiich is united into 
colonies (called coenolia), which swim about freely in the 
water {A, Fig. 149). Each colony consists of sixteen rounded 
or pointed cells (called zoogonidid), each provided with two 
cilia, and united into a spherical mass by a gelatinous enve- 
lope, through which the cilia project. Each zoogonidium 
breaks itself up into sixteen new zoogonidia, forming sixteen 
small and new colonies {B, Fig. 149), which are soon set free 
by the absorption of the common envelope of the colonies. 
The process of colony-formation just described is repeated 
again and again, thus giving rise, asexually, to a large num- 
ber of colonies. 

294. — The sexual process begins in the same way ; but the 
zoogonidia of the new colony separate by the softening of 
the colony-envelope ( C and D, Fig. 149), becoming zoospores, 
which are naked protoplasm-masses, which swim about by 
means of their cilia. After a time two zoospores meet, their 
points coming in contact, and their bodies soon fusing into 
one common body {E, F, G, Fig. 149). The result of this 
union, which is regarded as a very simple kind of sexual 



222 



BOTANY. 



act, is that within a short time a thick coat of cellulose is 
formed over the new cell, thus producing a zygospore {H, 
Fig. 149). After a long period of rest, these zygospores 




Fig. 149. — Pandorina Morum. A, non-sexual colony (or coenobinm) of 16 zoogoni- 
dia ; a, red spot ; &, transparent anterior end of zoogonidium, to which the two 
cilia are attached. 

B, sixteen young sexual colonies about to leave the gelatinous wall. 

(7 and T), colonies of sexual zoospores escaping. 

E^ F, G, conjugating zoospores 

H, zygospore in lesting stage (red). 

J, K, germinating zygospore, the contents escaping as a large red ciliated swarm- 
?pore. 

L. ncT colony formed by the division of A", very young stage. 

M, the same colony as Z, in a further stage of development.— After OErsted. 

germinate by the bursting of the coat (exospore), when the 
protoplasmic contents escape as a ciliated swarm-spore {K, 
Fig. 149). After swimming about for some time, the swarm- 



I 



ZOOSPORES, 223 

spores absorb their cilia, and surround themselves with a 
gelatinous envelope, when each breaks up into sixteen cells 
(zoogonidia) and gives rise to a new colony (L and if. Fig. 
149). 

Pandorina is nearly related to Yolvox (see p. 243), from 
which it seems a violence to separate it. It occurs in pools 
of fresh water (in Europe) as minute green spherical coenobia, 
3 mm. (.012 inch) in diameter. 

295. — Hydrodidyon, the Water Net, is a common plant 
in ponds and sluggish streams. It is, when full grown, a 
tubular net, composed of a multitude of elongated cells, 
which are attached only at their ends ; the net sometimes 
attains a length of 25 to 30 centimetres (10 to 12 inches), 
and the cells which com230se the meshes are in such speci- 
mens 7 to 8 mm. (^ inch) long. The 
reproduction is as follows : The pro- 
toplasmic contents of certain cells 
break up into a large number of 
daughter - cells - (macrozoogonidia), 
there being often as many as 7000 to p^^ iso.-part of a ceii of 
20,000: these soon arrane^e them- Wrodictyon ntricuiatmnm 

' ' o which the macrozoogonidia 

selves within the mother-cell so as are beginning to arrange them- 

. ^ , selves so as to form a minia- 

tO lOrm a miniature net [hm. loO), ture net within tue mother- 

, . , . „ Till 1 j_- i? cell.— After (Ersted. 

which IS treed by the absorption oi 

the walls of the mother-cell. Under favorable conditions 
the young net attains fall size within a month. A second 
mode of reproduction is known, or partly known. In cer- 
tain cells, in the division of their protoplasmic contents, in- 
stead of giving rise to the comparatively large macrozoogo- 
nidia, they produce an extremely large number (30,000 to 
100,000) of very small ciliated swarm-spores (zoospores, or 
the chronizoospores of Pringsheim), which, after SAvimming 
about for a time, acquire thick walls, and fall to the bottom 
of the water, where they remain in a resting state. Upon 
their germination they pass through a number of curious 
stages, and finally give rise to small nets. Suppanetz is said 
to have witnessed the conjugation of the swarm-spores within 
the mother-cell, or immediately after their emission."^ 

* Qr. Jour. Mx. Science, 1875, p. 399. 




224 



BOTANY. 



296. — Closely related to Hydrodictyon is Pediastrum (Fig. 
151), which consists of n number of cells arranged into a 
flat, thallus-like mass. The cells at a certain stage produce, by 




Fig. 151. — A. a colony of cells constituting a so-called individual of Pediastrum, 
granulatwm ; t, cells with their contents remaining ; the white cells are empty, their 
contents having escaped by the slits sp : g, contents of a cell (macrozoogonidia) 
escaping B, macrozoogonidia g, in the motile state, enclosed in the membrane b. (7, 
the macrozooifonidia arranging themselves in a colony, siill enclosed by the mem- 
brane b. X 400.— After Brauii. 

internal cell-division, a large number of daughter-cells, which 
are of two sizes. The function of the smaller ones is un- 
known ; the larger ones 
(macrozoogonidia) escape 
by a slit in the wall of the 
mother-cell, surrounded by 
a thin membrane, in which 
they swim freely for a time 
(Fig. 151 B). After a 
while they lose their pow- 
er of motion and arrange 
themselves symmetrically, 
as in C, Fig. 151. They 
soon grow together, and 
thus form a colony like 
the parent one. 

297. — In Cladopliora 
(one of the common Confervaceae) the cells of the branching 
filaments break up into ciliated zoospores which directly 




rs 1 -T t fill ui , 

cells filled with zoospores (zoogonidia) ; &, 
opening in cell-wall, by which the zoospores 
escape from the cells; c, zoospores (zoogo- 
nidia).— After GErsted. 



DESMIDIACE^. 225 



reproduce new filaments. Smaller bodies — swarm-spores — 
are also produced, and these are said to conjugate.* 

298. — In Ulva the plant-body is flat, and composed of a 
single layer of polyhedral cells, in which are found zoospores, 
which are asexual (Fig. 152, c), and smaller swarm-spores, 
which are said to conjugate, f [See foot-note on p. 242.] 



§ II. Class Cokjugat^. 

299. — In this class the sexual process is a distinct conju- 
gation, and it always takes place in the mature plant. 
Swarm-spores are wanting. The orders of this class are well 
marked. 

300.— Order Desmidiaceae. The Desmids are minute uni- 
cellular algae ; the cells are of Tery various forms, mostly 
more or less constricted in the middle, and divided into two 
symmetrical half-cells ; they are free, or united into loose 
families, sometimes involved in a jelly. The cell-wall is 
more or less firm, but not silicious. 

301. — The reproduction of Desmids takes place asexually 
and sexually. In the first the neck uniting the two halves 
of the cell elongates and becomes divided by a transverse 
partition, so that instead of the original symmetrical cell 
there are now two exceedingly unsymmetrical ones ; these 
grow by the rapid enlargement of the new and small halves ; 
eventually the two cells become symmetrical, by which time 
they have separated. This process, which is essentially fis- 
sion, may be repeated again and again. 

The sexual process takes place in this way : each of 
two cells which are near one another sends out from its 
centre a conjugating tube, which meets the corresponding 
one from the other {d, Fig. 153). At the point of meeting 
the two tubes swell up hemispherically, and finally, by the 
disappearance of the separating wall, the contents unite and 
form a rounded zygospore (e. Fig. 153), which soon becomes 



* and f. Areschoug, in " Observatioues Pliycolofjicse," 1874, records 
having' seen the conjugation in Cladophora and Ulva. 



226 



BOTANY. 



coated with a tliick wall (/, Fig. 153). This zygospore is a 
resting spore, and may retain its vitality for an indefinite 
period. 

302. — In the germination of the zygospore the first notice- 
able change is the partial separation of the contents into two 
2)ortions, and the escape of the whole, surrounded by a deli- 
cate wall, through a rent in the exospore {y, h, Fig. 153) ; 
the separation of the protoplasm now becomes complete 
(/, Fig. 153), and each portion becomes again partly divided 
by lateral constrictions, which, however, do not quite reach 
the centre ; in this way, within the mass which escaped from 
the zygospore there are formed two constricted cells, which 




Fig. 153.— Conjugation of Cosmarium Menenghimi. a, front ; b, end ; c, side 
view of the adult plants ; d, two cells conjugating ; e, young zygospore formed ; /, 
ripe zygospore, with spiny wall— the four halves of the parent cells are empty ; (7, 
the zygospore germinating after a period of rest ; h, the young cell escaped froin 
zygospore ; i, young cell dividing, showing two new plants similar to a, placed 
crosswise in the interior of the cell, x 475.— After GErsted. 



are, in fact, new individuals resembling the original ones 
which conjugated {a, h, c. Fig. 153). 

The descriptions above given are of the processes as they 
take place in the bilobed Desmids ; in those which are not 
lobed it takes place in essentially the same way, with differ- 
ences only in the minor details. 

303. — Desmids have the power of slow locomotion, and 
they may often be seen moving across the field of the micro- 
scope, or in a jar or bottle they may frequently be seen to 
congregate in j)articular places. The mechanism of the 
movement is unknown, but it appears to be certain that it is 
not ciliary. 

Desmids are exclusively inhabitants of fresh water (not 
salt), and in almost all cases they appear to prefer pure and 



DIATOMAGE^. 227 

clear water to that wliicli is stagnant, although they are to be 
found in the latter also. 

Tlie principal genera are Cosmarium (Fig. 153), Euastrum and 
Micrasterias, wliicli are constricted in the middle ; and Glosterium, in 
which the individuals are cylindrical or fusiform.* 

304.— Order Diatomacese.f The Diatoms are micro- 
scopic unicellular algae, resembling in many particulars the 
Desmids, but differing from them in having walls which are 
silicified, and in the chlorophyll being hidden by the pres- 
ence of phycoxanthine. The endochrome, as the colored 
contents are called, is always symmetrically arranged. Each 
cell (technically called a frustule) is usually composed of two 
similar and approximately parallel portions, called the valves. 
Each valve may be described as a disc whose edge is turaed 
down all around, so as to stand at right angles to the remainder 
of the surface, making the valve have the general plan of a pill- 
box cover. The two valves are generally slightly different 
in size, so that one slips within the other {A, Fig. 154), thus 
forming a box with double sides. In other cases — as, for ex- 
ample, in Diatoma and Fragilaria — the valves are simply 
op230sed, and do not overlap. In figures and descriptions of 
Diatoms, the parts corresponding to the top and bottom of a 
box are referred to as the valves, or as the side vietu {0, Fig. 
154), and that which in the box would be called the side, is 
in the Diatom called the front. 

305. — The individuals may exist singly, or in loose fami- 
lies ; they are free, or attached to other objects by little 
stipes, and they are frequently imbedded in a mucous secre- 
tion. The free forms are locomotive, and may be seen in 
constant motion under the microscope. As in the Desmids, 
the mechanism of this movement is not certainly known ; 



* The student is referred to Rev. Francis Wolle's "Desmids of 
the United States," 1884, for an account of our species. 

f Most of our species are figured and described in Henri Yan 
Heurck's "Synopsis des Diatomees de Belgique," 1880-5. Wolle's 
' • Diatomacese of North America" (1890) will prove useful in the study 
of our species. 



'^2b 



BOTANY. 



the most probable explanation is that it is due to protrusions 
of tlic protoplasm through orifices in the rigid wall. 

306. — Diatoms bear a close resemblance to the Desmids 
in their modes of reproduction ; the differences that exist 
are easily referable to the differences in the wall. The 
asexual reproduction is a true fission, although at first sight 
it might not be recognized as such. The protoplasmic con- 
tents of the cells divide in a plane parallel to the valves •, 

each portion then forms a 
new valve in the plane of the 
division. As during this pro- 
cess the two original valves are 
pushed apart the new valves 
are fitted, the one into the 
larger and the other into the 
smaller one {B, Fig. 154). By 
a slight subsequent increase 
of their contents, the two 
daughter- cells are pushed out 
so as to be free from each 
other ; in many cases they sep- 
arate, while in others they re- 
main in contact, although 
really free. This process re- 
quires from three to four days 
for its completion. It will 
readily be seen that the con- 
tinued formation of individu- 
als in this way must result, in all species whose valves are of 
a slightly unequal size, in producing smaller and smaller 
cells. This reduction of size does not, however, take place 
in those species whose valves are simply ojoposed, as in Dia- 
toma. The reduction of size is corrected by the formation 
of what are termed auxospores ; * these are large individu- 
als, which form either by an asexual or a sexual process. 
The asexual formation of auxospores takes place by the 




Fig. IM.—N'avicvla viricUs. A, front 
view of a frusiule ; J3, front view of a 
frustnle undergoing fission ; C. side view 
of a frustule, sliowing tiie central line, 
called the raphe, the central and termi- 
nal nodules, and the surface markings. 
—After CErstcd. 



* From tlie Greek av^dvu, to increase. 



i 



DIATOMACE^^. 



229 



protoplasm of one of the small Diatoms leaving its silicious 
shell (the latter falling apart), and then increasing by growth 
until it reaches the normal size, when it forms a new coat 
abont itself. This is not nnlike what has been called the 
Eejuvenescence of the cell. (See p. 42.) 

307. — The second mode of the formation of auxospores is 
a sexual one, and is, in fact, the sexnal mode of reproduc- 
tion above referred to.* Two individuals come near each 
other ; their valves separate, and the two protoplasm-masses 
unite with each other into one mass, or in many cases two 
masses {A, Fig. 155). These new masses develop directly 
into auxospores, the whole process 
requiring from ten to fourteen 
days {B, Fig. 155). 

308. — Diatoms are exceedingly 
abundant ; they occur in both 
salt and fresh water, usually 
forming a yellowish layer at the 
bottom of the water, or they are 
attached to the submerged parts of 
other plants, and to sticks, stones, 
and other objects ; they have been 
dredged from the ocean at great 
depths, and appear to exist there 
in enormous quantities. They are showing conjugation and forma- 

T „ -, -^ 1,1 tiou of auxospores. A, conjuga- 

also round among mosses and other tion of two fmstuies ; b, two aux- 

1 , . , 1 , ospores, with the four valves of 

plants on moist ground ; great the two parent frustules.-After 

numbers occur as fossils, forming ^''^*^*^- 
in many instances vast beds composed of their empty 
frustules. The varied and frequently very beautiful mark- 
ings of their valves have long made Diatoms objects of 
much interest to the microscopist. The great regularity 
and the extreme fineness of the lines and points upon some, 
have caused them to be used as microscopic tests. The 




Pig. 155.— JSTamcula saxonica. 



* This process takes place at certain seasons of the year for each 
species ; according to Professor H. L. Smith, in Gomphonema oUvaceum 
it occurs in February and March. 



230 BOTANY. 

fineness of some of these markings is astonishing, as will 
be seen from the following list : 

^•Pleurosigma Balticum 0006 mm. (.000026 inch). 

PleuTodyma angulatam 0005 " (.000019 " 

Navicula rhomboides 0004 " (.000015 " 

Amphipleurapellucida 0002 " (.000008 " 

(a) The classification of Diatoms is as yet largely artificial. That 
proposed by Professor H. L. Smith f is one of the most satisfactory ; it 
is based upon the structure of the frustule. He divides the order into 
three tribes, each containing several families, as follows : 

Tribe I. Raphidie^. 

Frustules mostly bacillar (i.e., longer than broad) ; always with a dis- 
tinct raphe or median line on one or both valves, and with central and 
terminal nodules ; without teeth, spines, awns, or processes. 

Family 1. Cymbelleee. Raphe mostly curved ; valves alike, more 
or less arcuate, cymbiform (i.e., lunate). 

Illustrative genera. Amphora, Cymhella. 

Family 2. Naviculese. Valves symmetrically divided by the 
raphe ; frustules not cuneate or cymbiform. 

JSfamcula (Figs. 154 and 155), Stauroneis, Pleurosigma, Amplii- 
pleura. 

Family 3. Gomphonemeee. Valves cuneate ; central nodule un- 
equally distant from the ends. 

Gomplionema, Bhoicosphenia. 

Family 4. Achnanthese. Frustules genuflexed ; nodule or stau- 
ros on one valve ; mostly stipitate. 

AcJinantTies, AcJmanthidmm. 

Famiily 5. Cocconide£e. Frustules (generally parasitic) with valves 
unlike ; valves broadly oval. 

Cocconeis, Anortlieu. 

Tribe II. Pseudo-Raphidie^. 

Frustules generally bacillar {i.e., longer than broad) ; valves with- 

* These measurements are those given in Carpenter's work on *' The 
Microscope," fifth edition, p. 212. Those given by Professor Morley, in 
Am. Naturalist, 1875, p. 429, are a trifle less in each case. 

f " Conspectus of the Families and Genera of the Diatomaceae," by 
H. L. Smith, published in The Len^, 1872-3, and republished in Le 
Microscope, si construction, etc., by Henri Van Heurck, 1878. 

The brief sketch of this system of classification here given is fur- 
nished by Professor Smith. 



DIATOMAGE^. 231 

out a true raphe ; without central and marginal nodules ; without 
teeth, processes, or spines. 

Family 6. Fragilarieae. Frustules adherent, forming a ribbon- 
like, fan-like, or zigzag filament, or attached by a gelatinous cushion 
or stipe ; sometimes arcuate in front, or side view. 

EpitTiemia, Eunolia, Fragilaria, Synedra, Diatoma. 

Family 7. Tabellariese. Frustules with internal plates, or imper- 
ifect septa, often forming a filament. 

GUmacosphenia, GrammatopJiora, Bhdbdonema, Tabellaria, Stria- 
tella. 

Fam.ily 8. Surirelleae. Frustules alate, or carinate ; frequently 
cuneate in front view and side view. 

MitzscMa, Surirella, Cymatopleura. 

Tribe III. Crypto-Raphidie^. 

Frustules cylindrical or angular ; frequently with processes, spines, 
teeth, or awns ; and often coherent, forming a filament. 

Fam.ily 9. Chaetocereae. Frustules mostly hyaline and armed 
with bristles or awns, and generally coherent. 

Rhizosolenia, Ghcetoceros. 

Fam.ily 10. Melosireee. Frustules cylindrical, adhering and form- 
ing a stout filament ; valves cylindrical, sometimes armed with spines. 

Melosira, Stephanopyxis. 

Fam.ily 11. Biddulphieae. Frustules adherent, forming generally 
a zigzag filament, attached by one or two processes. 

Isthmia, Terpsinoe, Biddulphia, Hemiaulus. 

Family 12. Eupodiscese. Frustules not forming a filament ; 
valves cylindrical, with ocelli ; often with radial ribs or furrows. 

Auliscus, Aulacodiscus, Eupoducus. 

Fam.ily 13. Heliopelteas. Valves divided into compartments al- 
ternately light and dark, often with marginal spines or teeth. 

Actinoptychus, HeUopeU% Halionyx. 

Family 14. Asterolampreae. Valves circular (rarely angular) and 
I mostly hyaline, with linear, often bifurcating, rays. 
I Actinodiscus, Mastogonia, Asterolampra. 

j Family 15. Coscinodiscege. Valves circular, generally with radi- 

|: ating cellules, granules, or punctse ; sometimes with marginal or intra- 
marginal spines or distinct ribs ; without distinct processes. 

GyclottUa, Actinocydun, Stephanodiscus, Arachnoidiscus, Goscino- 



(6) Diatoms are very easily obtained for study ; it is only necessary 
to scrape oflf a little of the slippery covering of submerged stones or 
sticks to procure numerous specimens. They may be obtained also 
from ordinary drinking water, allowing it to flow from a hydrant 
through a filter of " Canton flannel " for an hour or so. Often appar- 



232 BOTAITY. 

ently pure water placed for a few weeks in a clean bottle and exposed 
to the light will yield an abundant crop, generally of one species. 

309.— Order Zygnemacese. The plants of this order are 
elongated luibrancbed lllaments, composed of cylindrical 
cells arranged in single rows. The cells are all alike, and 
each one appears to be independent, or nearly so, of its asso- 
ciates. The filament is thus, in one sense, rather a com- 
posite body than an individual. Each cell has usually a 
centrally placed nucleus, with radiating extensions of the 
protoplasm passing from it to the layer lining the inner sur- 
face of the wall. The chloro^^hyll is generally arranged in 
bands or plates, but under certain conditions it exists in 
shapeless masses. 

310. — The vegetative increase of the number of cells takes 
place by the fission of the previously formed cells. The 
protoplasm in a cell divides, and a plate of cellulose forms in 
the plane of division. This is repeated again and again, and 
by it the filament becomes greatly elongated. It is interest- 
ing to note that this increase of cells, which here constitutes 
the growth of the plant-body, is that which in simpler plants 
is called th^ asexual mode of reproduction. In the plants 
under consideration there is barely enough coherence of the 
cells to enable them to constitute a plant-body, and one can 
readily see that the same fission of the cells which now takes 
place, and which here increases the size of the plant, would, 
if the cells cohered less, simply increase the number of indi- 
viduals. 

As might be expected, the filaments occasionally separate 
spontaneously into several ^^arts of a considerable length, 
and the parts floating away give rise to new filaments. The 
separation takes place by the cells first rounding off slightly 
at the ends, so that their union is weakened at their cor- 
ners ; finally only the centres of the rounded ends are left 
in slight contact, which soon breaks. 

311. — The sexual reproduction is well illustrated in /S^f- 
rogyra, one of the principal genera. At the close of their 
growth in^the spring, the cells push out little processes from 
their sides, which extend until they come in contact with 



ZYGNEMAGE^. 



233 



similar processes from parallel filaments (a, h, Fig. 156). 
Upon meeting, the ends of the processes flatten upon each 
other, the walls fuse together, and soon afterward become 
absorbed, thus making a channel leading from one cell 
to the other (Fig. 157). Through this channel the proto- 




FiG. 156. 

Fig. 156.— Beginning of the process of coujugation m Spirogyra longata. «, 
beginning of the formation of lateral tubes ; b, c, the tubes in contact. X 550. 
—After Sachs. 

Fig. 157.— Conjugation of Spirogyra longata. A, the protoplasm passing from 
one cell to the other at a ; b, the mass of protoplasm formed by the union of the 
protoplasmic contents of the two cells. 

B, two young zygospores (c), each with a cell-wall. They contain numerous oil 
drops, and are still enclosed by the walls of the parent cell, x 550.— After Sachs. 

plasm of one cell passes into the other, and the two fuse into 
one mass, which becomes rounded, and in a short time secretes 
a wall of cellulose around itself (Fig. 157, ^ and B). The 
zygospore thus formed is set free by the decay of the dead 



234: BOTANY. 

cell-Wcills of the old filament surrounding it ; it then falls to 
the bottom of the water and there remains until the proper 
conditions for its growth appear. 

312. — The conjugation described is the one best known ; 
it prevails in a large part of the genus mentioned. There 
are some curious modifications of the process. In what is 
called genuflexous conjugation the opposing cells of parallel 
filaments become strongly bent back so as to form an angle 
at their central points ; then the angles approach each other 
and fuse, allowing the cell-contents to p>ass over, as in the 
other case. 

Lateral conjugation takes place between the cells of the 
same filament. At the contiguous ends of two cells tubular 
processes are pushed out, w^hich, meeting, form a curved 
channel from one cell to the other. Occasionally there ap- 
pears to be only a slight enlargement of the contiguous ends 
of the cells, and this is followed by the breaking away of a 
portion of the separating wall. These cases of lateral con- 
jugation show that the cells are, to a great extent, to be re- 
garded as independent organisms, and that the conjugation 
is primarily the union of two cells, instead of two filaments. 

313. — The germination of the zygospore is a simj^le pro- 
cess. The inner mass enlarges and bursts the outer hard 
coat; it then extends into a columnar or club-shaped mass, 
gradually enlarging upward from its point of beginning ; 
after a while a transverse 23artition forms in it, and this 
is followed by another and another, until an extended fila- 
ment is formed. 

{a) The principal genera are Spirogyra, in wliich the clilorophyll 
bands are spirally arranged in the cells, and Zygnema, in which the 
chlorophyll is usually arranged in a stellate manner. Thirty-nine 
species of Spirogyra are recorded as occurring within the United 
States, and of these 8p. longata and Sp. quinimi are the most common. 
Of Zygnema six species are recorded in the United States, several of 
which are common. 

(&) These plants may be found at any time in ditches and streams, 
where they often form extensive masses of green felt ; but it is only 
from the middle to near the end of spring that they can be found in 
conjugation. For the Xorthern States the time varies from April t<y 
the first of June ; in the South it is of course much earlier, being in. 



MUCORINI. 235 

Florida as early as February, In searching for conjugating specimens 
only tlie yellow and brown masses of filaments need be examined, as 
the process never takes place in the bright green ones. 

314. — In the genera Mesocarpiis and Phurocarpiis the 
conjugation is slightly different from that described above. 
The conjugating tube, which is much longer, becomes di- 
lated midway between the two filaments, and in this the 
contents of the two cells unite and form a zygospore. This 
difference has been considered by some botanists to be of 
sufficient importance to set off these genera in a group allied 
to, but distinct from, the Zygnemacese. When they are so 
set off they constitute the Mesocarpece ; but it is altogether 
probable that they are to be considered rather as a subdivi- 
sion of the Zygnemaceae than as a distinct order. 

Mesocarpus scalaris is our most common species. In general appear- 
ance it resembles the previously mentioned species, but its chlorophyll 
is not so regularly arranged. 

315.— Order Mucorini. The Moulds are saprophytic and 
sometimes parasitic j^lants ; they are composed of long 
branching filaments {JujioIkb), which always form a more or 
less felted mass, the mycelium ; when first formed the hyphse 
are continuous, but afterward septa are formed in them at 
irregular intervals. The protoplasmic contents of the hy- 
phae are more or less granular, but they never develo|) chlo- 
rophyll. The cell-walls are colorless, except in the fruiting 
liyphae, which are usually dark colored or smoky (fuliginous). 
The mycelium sometimes develops exclusively in the inte- 
rior of the nutrient medium ; in other cases it develops 
partly in the medium and partly in the air. In some species 
the mycelium may occasionally attach itself to the hyphse 
of other plants of the same order, and even to nearly related 
species, and derive nourishment parasitically from them. It 
is doubtful, however, whether any Moulds are entirely 2:)ara- 
sitic, and so far as parasitism occurs it appears to be con- 
fined to narrow limits ; none, so far as known, are parasitic 
upon higher plants. 

316. — The reproduction of Moulds is asexual and sexuaL 
In the asexual reproduction the mycelium sends up erect 



236 



BOTANY. 




Fig. 158.— Diagram showing the mode of growth 
of Mucor Mucedo. m, the mycelium ; s, single 
sporangium, borne on an aerial erect hypha.— After 
Prantl. 



liyplia), wliicli produce few or many separable reproductive 
cells — the spores (Fig. 158). The method of formation of 
the spores in Miocor Mucedo is as follows : the vertical hy- 
phfe, which are filled with protoplasm, become enlarged at 
i5"^ M the top, and in each 

a transverse partition 
forms {A, a, Fig. 159), 
the portion above the 
partition (h, Fig. 159) 
becomes larger, and, 
at the same time, the 
transverse partition 
arches up {B, a, Fig. 
159), finally aj)pearing 
like an extension of 
the hypha, then called 
the Columella (C, a, 
Fig. 159). The pro- 
toplasm in the en- 
larged terminal cell (b) divides into a large number of 
minute masses, each of which surrounds itself with a cell- 
wall ; these little cells are the spores, and the large mother- 
cell is now a sporangium. 

In the other Moulds the process is essentially like that 
in 3fucor Mucedo. In j^ -q 

many cases there are sev- jf^ 
eral sporangia formed at 
the top of the vertical 
hyphse ; in such cases the 
latter are branched before 
the formation of sporan- 
gia. Another variation 
from the method as de- 
scribed above is that in 
some species but one spore 
is formed in each sporan- 
gium ; the hyphae then appear to bear naked spores. 

317. — The spores are set free in different ways ; in some 
cases the wall of the sporangium is entirely absorbed by the 
time the spores are mature ; in other cases only portions of 



■h 




Pig. 159.— Diagi'ams showing mode of 
growth of the sporangium of Mucor Mucedo. 
A, very young stage ; B. somewhat later ; C. 
sporangium with ripe spores, a in all the fig- 
ures repi'esents the partition wall between the 
last cell of the filament and the sporangium b. 



MUCORINL 



237 



the sporaugiiini-wall are absorbed, producing fissures of ya- 
rious kinds — e.g., at the base in Pilobolus j about the middle 
in Circinella j irregular in Mucor, etc. The spores germi- 
nate readily when on or in a substance capable of nourishing 
them (but not in pure water) ; they send out one or two hy- 
phae (sometimes one from each end), which soon branch and 
give rise to a mycelium. Spores may, if kept dry, retain 
their vitality for months. 

318. — A second kind of asexual formation of spores takes 
place in some, if not all, the genera of the Mucorini. The 



y 





Fig. 160.— Conjugation of JIfMCor sfolonifer. «, two hyphse near each other, and 
sending out short lateral processes or branches, which come in contact ; b, the 
branches grown larger ; c, the formation of a partition near the end of each branch ; 
d, absorption of the wall between the two branches, and the consequent union of 
the protoplasm of the end cells; e, zygospore fully formed, e X 90; the others 
nearly the same.— After De Bary. 



protoplasm in certain parts of the hyphae condenses and be- 
comes transformed into single reproductive bodies, known as 
chlamydospores. Occasionally they form at the ends of 
hyphse, and are then apt to be mistaken for the '* fruiting" 
of other fungi. 

319. — Sexual reproduction takes place after the produc- 
tion of asexual spores ; the mycelium produces at particular 
points, in the air or within the nutritive medium, two simi- 
lar branches, which come in contact with each other, and by 
fusing their contents give rise to a zygospore (Fig. 160), 



238 



BOTANY. 



The stci^s in the process in Mucor stolonifer are briefly as 
follows : two liyphae come near each other, and send out 
small branches, which come in contact with each other («, 
Fig. IGO) ; these elongate and become club-shaped, and at 
the same time they become more closely united to each other 
at their larger extremities (l, Fig. 160); a little later a trans- 
verse partition forms in each at a little distance from their 
place of union (c. Fig. 160) ; the wall separating the new 
terminal cells is now absorbed, and their protoplasmic con- 
tents unite into one common mass {d, Fig. 160) ; the last 
stage of the process is the secretion of a thick wall around 
the new mass, thus forming a zygospore (e, Fig. 160, and z, 
Fig. 161). 

It is interesting and instructive to note here the close simi- 
larity between the zygospore of Mucor stolonifer and that of 
Mesocar;pus, briefly described above (par. 314). In both the 

zygospore is formed in the lateral 
tranclies of the ordinary filaments. 
320. — In Pi2)toce2)Jialis the for- 
mation of the zygospore is essen- 
tially like that in Mucor, with 
some minor differences. The 
uniting hypha-branches are large 
and curved, and are smaller at 
their points of union ; the zy go- 
Fig. i6i.-Zygospore, z, of Mu- sporc is f omicd at first in the 

cor; m, mycelium.-After Prantl. ^^^^^ ^^^^ formed by the Uniou of 

the tips of the branches, but it soon grows so much as to 
appear to be external {Z, Fig. 162). In this, as in all other 
cases, however, the zygospore is strictly an endogenous for- 
mation. 

" The zygospore does not germinate until it has under- 
gone desiccation, and has experienced a certain period of 
rest,"* when, if placed in a moist atmosphere, it sends out 
hyph^ which bear sporangia. The zygospores appear never 

* "Researclies on the Mucorini," by Pli. Van Tiegbem and G, Le 
Monnier (translated in Quarterly Journal cf M^'croscopical Science, 
1874, p. 49), upon wliidi most of what is here said about the Moulds is 
based. 




mi^'' 



MVGOItmi. 



239 



to form a mycelium ; that is always the result of the 
growth of spores from the sporangia. 

{a) In the study of the Moulds it is almost always necessary to make 
use of alcohol for freeing the specimens of air ; afterward they usually 




Fig. 162.— Piptoeephalis Freseniana, parasitic npon the liypiise, M., M, M, of 3fucor 
Mucedo. m, m, parasitic hyplise, attaclied to tlieir liost by the haustoria, h ; c, conid- 
ial spores ; s, s, the two branches which conjugate and form the zygospore, Z. Highly 
magnified.— After Brefeld. 

require to be treated with a dilute alkali, as a weak solution of am- 
monia or potassic hydrate, which causes the hyphae to swell up to their 
original proportions before drying ; care must be taken that the hyphas 
and spores are not unduly swollen, or serious mistakes may be made. 

(&) In the careful study of the Moulds it is necessary to resort to arti- 
ficial cultures of the different species, in order to be able to follow them 



240 BOTANY, 

tlirougli all their clianges. The spore of a particular species must bp 
sown, and the development of hyphse, mycelium, sporangia, etc., care* 
fully followed ; and the greatest care must be taken to guard against 
error from the accidental presence of other species. 

{c) " Pan culture," which consists in sowing the spores upon or in the 
nutritive medium in pans or deep plates covered by bell-jars, must always 
be resorted to, even if more accurate cultures are also made. By placing 
a quantity of horse-dung in a pan under a bell-jar, there will soon be 
obtained a good supply of vigorous Moulds ; sometimes several species 
may be obtained from a single pan. By care a few sporangia of each 
species may be obtained from this first culture, vt^ith little probability 
of contamination with other species. These are to be used for more 
careful cultures. 

{d) If now moistened pieces of fresh bread are placed under a bell- 
jar, and a few of the spores of a particular species are sown on them, 
the growth and successive stages of development may be easily fol- 
lowed. Instead of bread, other materials may be used, as stewed 
prunes and other fruits, pieces of oranges or lemons, etc., and for cer- 
tain species the half-cleaned bones of beef from the kitchen. 

(e) Where still greater care is desirable, the nutritive media may be 
prepared by boiling and filtering, after which they are placed in thor- 
oughly cleaned pans or plates, and covered by clean bell-jars ; in these 
are placed pieces of hardened plaster of Paris or earthenware (porous), 
which have previously been heated so as to destroy all spores, and upon 
them are sown the selected spores. The sources of error are in this 
way very much reduced, but it must be borne in mind that they are by 
no means all eliminated ; hence the student must be constantly on the 
lookout for other species than the one under culture. 

(/) The media recommended by Van Tieghem and Le Monnier are, 
(1st) boiled and filtered orange juice, which, being acid and saccharine, 
is not so liable to be invaded by other common Moulds ; (2d) a decoc- 
tion of horse-dung, boiled and filtered ; this is neutral and alkaline, and 
serves as a medium for many species; but it is open to the objection 
that it is liable to the invasion of intruding species ; (3d) a saline solu- 
tion of the following composition : 

Calcium nitrate 4 parts. 

Potassium phosphate. 1 ** 

Magnesium sulphate 1 '* 

Potassium nitrate 1 " 

Distilled water 700 *' 

[Sugar 7 parts, j 

In some cases the sugar may be omitted. 

(g) The most accurate and satisfactory, but at the same time most 
difficult cultures, are cell-cultures. These are made as follows : glass, 
tin, or India-rubber rings four to five millimetres high are fastened to 



MUCORINL 



241 



ordinary orlass slides ; a very little water is placed in tlie bottom of the 
cell so formed, to keep tlie air in it always moist ; a small drop of tlie 
nutrient liquid, free from spores of any kind, is placed in the middle of 
a cover-glass of the proper dimensions, and in this a single spore of 
some particular Mould is placed ; the cover-glass is now inverted over 
the cell, and held in place by a minute quantity of oil on the edge of 
the cell. The preparation must be placed in a warm and saturated 
atmosphere. An ordinary bell-jar set over a plate of water, or better 
still, of wet sand, will furnish a very good moist chamber. The appa- 
ratus used by Van Tieghem and Le Monnier is, however, in many re- 
spects the best that has yet been devised (Fig. 163). 

By means of such cultures as this, the student may follow all the de- 
tails of the germination, and after-development of any particular 
spore, as all that is necessary to do is to remove the slide from the 
growing box, and, without disturbing the cell, to place it under the 
microscope ; the same specimen may thus be examined any number 
of times, with the least possible liability of error. 

Qi) The most common Moulds are species of the genus Mucor. J£ 



c= 


a 


I 


.- • • ^ 


==3- . 


h^^ 


i ir«^i! <^ 


II^T^II-c ■■ \ 


,h 


,*Tr_ 










!■:: 


:•^:■::>-^• ••••^^•V■^ 





Fig. 163.— Section of a]}paratTis for cell cultures. The shaded portion represents a 
section of a tin or zinc box ; a, a, the supporting ledges ; b, h, the glass slips ; c, c, 
glass or metal rings fastened to the glass slips, seen in section, and covered with a 
piece of thin glass : g, plate of glass, covering the box. The dotted line shows the 
height of the moist sand with which the bottom of the box is covered. 

Mucedo and M. stolonifeT (if distinct) are common on many decaying 
substances. M. Syzygites occurs on decaying Agarics and Polypori. 
Piloholus crystalliaiLS, Piptocephalls Freseniana, and GhcBtodadmrn 
Jonesii occur on animal excrement. Phycomyces nitens grows on oily or 
greasy substances, as old bones, oil casks, etc. 

319a.— Order Entomophthoraeese. The Insect Fungi 
are well represented by the My Fungus {Empusa musccp) 
which is so destructive to house-flies in the autumn. It 
consists of small tubular cells which penetrate the tissues 
of the fly and at length pierce the skin and produce minute 
terminal spores (conidia). These give the fly the familiar 
powdery appearance, and surround it, when dead, with a 
whitish halo. Spherical, thick-walled resting-spores have 
been seen (by Winter), but they are of rare occurrence in 
this species, though very common in others. There are six 
or eight genera {Empusa, EntomoiMliora, Tariclmim, etc.), 
and from forty to fifty species are known. 



242 



BOT.\yT. 



The Pii/EospoTiEiTi:, coutaining the kelp and its allies, are marine 
plants of an olive-brown color, varying greatly in size and structure, 
from minute hlamentous forms to the gigantic kelp with stems and 
leaves, often a hundred metres or more in length. In previous 
editions they were regarded as more nearly related to the Fucaceae 
[p. 364], but their reproduction by the conjugation of similar zoo- 
spores indicates their relationship to the zygophytic zoospores. They 
include the highest plants of the class. 

Twelve families, viz., Scytosiphoneoe, Punctariese, Desmarestieoe, 
Dictyosiphoneae, Ectocarpeae, Sphaeelarieae, Leathesiese, Chordarieae, 
Asperococcese, Ralfsieaj, Sporochneoe, Laminaiieae, are represented 
on the New- England coast by twenty-six genera and forty-eight 
species, wdiile many more occur on the Pacific coast, w^here the 
great bladder 'kel]) {Macrocystis pyrifera) ^OTRQiimts attains a length 
of two hundred metres or even more. 

Fossil Zygophytes. — In the Silurian period species of Lamin- 
a/rites, Ilarlania, etc., probably represented the Phaeosporeae, which 
order was also abundantly represented in the Devonian. Confervites 
occurs in the Jurassic, and in the Tertiary. Fossil diatoms of many 
species have been found in the Tertiary; at Richmond, Va., they 
form a vast bed nearly ten metres thick, and one at Monterey is 
sixteen metres in thickness. 

Arrangement of the Classes and Orders of Zygophyta. 






Conjugate. 



Zoospores. 



CHAPTER XVI. 

OOPHYTA. 

321. — The distinguisliing feature of the plants belonging 
to this division is that they develop a large cell (the oogo- 
nmm), differing from those about it in size and general ap- 
pearance, which contains one or more rounded masses of 
protoplasm (the oosplieres), which are subsequently fertilized 
by the contents of a second kind of special celt of much 
smaller size (the anther idium). The oogonium is the fe- 
male reproductive organ, and the antheridium the male. 
The protoplasm of the latter is in some cases transferred by 
direct contact to the oosj)here ; in other cases it is first broken 
up into motile bodies, the spermatozoids, which then come 
to and become fused with the oosphere. The oosphere itself 
is never motile, and in most cases it remains within the 
parent plant until long after it is fertilized. The result of 
fertilization is the production of an oospore, which differs 
from the oosphere structurally in having a hard and gener- 
ally colored coating, and physiologically in having the power 
of germination and growth after a period of rest of greater 
or less duration. 

322. — The plants of this division vary greatly as to the 
development of the plant-body. In some cases it is a feebly 
united colony ( Volvox and its allies), while in its highest 
forms it is a well-developed thallus, with even the beginning 
of a differentiation into Oaulome, Phyllome, and Eoot 
[Fucacece), 

§ I. VoLYOx AKD ITS Allies. 

323. — In the classification of the jolants of this division 
the lowest place must be assigned to Volvox and Eudovina, 
which, as previously stated, are, with doubtful propriety, 



244 BOTANY. 

separated from Pandorina. If the two genera are to be 
separated from Pandorina there can be but little doubt that 
their position must be in the very lowest part of the Oophy- 
ta. Such a position would indicate what is probable on 
other grounds also, that the divisions Zygophyta and Oophy- 
ta lie side by side as t\vo divergent systems, and that in 
their lowest members they almost, if not entirely, coalesce.* 
324. — Volvox glohator is a hollow sjDherical colony of uni- 
cellular algae, having a diameter of .5 to .8 mm (.02 to .03 
inch). Each individual of the colony is a flask-shaped cell 
of green-colored protoplasm, bearing two cilia upon its 
pointed extremity, and surrounded by a hyaline gelatinous 
envelope. These individuals are arranged so as to form a 
spherical surface, their hyaline envelopes being in contact 
with one another, and so placed as to bring the pointed ends 

of the green masses, with their 
cilia, to the surface. The 
sphere is thus made up of 
closely approximated individ- 
uals, which dot its surface, 
and whose cilia give to the 
whole colony a hairy appear- 
ance. The movements of the 
mg.i&i.— VoUoxgiobator. a, sperma- cilia givc to the Sphere a ro- 

tozoid, X 800. b, oogonium, with sper- , ,. i • i • n 

matozoids surrounding the oosphere, X tary motlOU, Whlch IS USUady 
400.-After Cohn. ^^^ ^f prOgTCSSion alsO. 

325. — The sexual reproduction of Volvox takes place in 
this way : some of the cells in a colony undergo conversion 
into spermatozoids, which are elongated club-shaped, and 
provided with two cilia {a, Fig. 164) ; other cells of the same 
colony, or of different colonies, become greatly enlarged into 
oogonia, consisting of an outer hyaline coat enclosing an 
inner rounded mass of dense and granular protoplasm {h, Fig. 
164). Upon the escape of the spermatozoids they penetrate 
the cavity of the colony (into which the oogonia have now 
pushed), and there coming in contact with the oogonia, they 

* It will not do violence to any laws of classification, based upon 
the general tlieory of evolution, to propose tliat VoUox, Eudorina, 




■^*m 



VOL vox AND ITS ALLIES. 



245 



bury themselves in the hyaline envelope, and finally pene- 
trate and become fused into the oosphere {h, Fig. 164). A 
thick wall now forms • upon the fertilized oosphere, and it 
becomes transformed into an oospore. Thus we have in 
these plants the transformation of an 
individual of the colony into an oogo- 
nium and oos^^here, and the subse- 
quent fertilization of the latter by 
spermatozoids^ which are themselves 
fractional parts of other members of 
the colony. 

326. — The relationship of the low- 
er Oophytes with the lower Zygo- 
phytes, as indicated by Volvox and 
Pandorina, is further shown by the 
position of SpJiceroplea, an undoubted 
relative of the Confervacece {Clado- 
pliora, etc.). Sphceroplea is a free, 
unbranched, filamentous alga, com- 
posed of long cells joined end to end 
(A J Eig. 165), It produces oospheres 
in some of its filaments, each cell 
producing several {B, Fig. 165). 
While these are forming in one set of 
filaments, in another the protoplasm 
becomes broken up into a multitude 
of elongated, bi-ciliate spermatozoids 
{G and G, Fig. 165) ; these escape 
through lateral openings in the cells, 
which are formed by the absorption 
of a part of the wall, and then swim- 
ming through the water they find 
their way to corresponding openings in the walls of the 




Fig. Wi.—Sphcm'opUa annvn 
Una. A, ordinary filament; 
r. chlorophyll masses. B, fila- 
ment consisting of oogonia, 
the contents breaking up into 
oospheres ; o, o, openings for 
entrance of spermatozoids ; 
s, s, spermatozoids entering the 
oogonia ; m and k, oospheres 
at the instant of fertilizat'on ; 
n, fertilized oosphi^res, now 
enclosed in a thin cell-wall. C, 
filament consisting of auther- 
idia ; s, s, the escaping sper- 
matozoids, issuing through the 
openings o o. D, an oospore 
with its thick coats of cellu- 
lose. E, zoospore (vegotniive 
zoogonidium). F, oosphere in 
the act of being fertilized by a 
spermatozoid, s. G. spcrmato 
zoids.— After (Eisted. 



and their ahies in the Oophyta, and Pandorina and its ahies in the 
Zygophyta, be placed in a common class Zcjosporese. This class 
would thus have two branches, one in the division Zygophyta, and 
the other in the Oophyta. Such an cirrangemeut would indicate i\i% 
evident relationship of the plants under consideration better than any 
yet proposed. 



2^6 BOTANT. 

cells, which contain the oospheres ; upon coming in contact 
with an oosphere they bury themselves in its substance, after 
which the oosphere secretes a thick wall, and thus becomes 
an oospore {D, Fig. 165). In germination (which takes place 
after a period of rest) the protoplasmic contents of the 
oospore become broken up into a large number of bi-ciliated 
zoospores having nearly the shape and general appearance 
of the spermatozoids ; these, after swimming about for a 
time, become gradually elongated into narrowly fusiform 
filaments, which are the young Splimroj^lea individuals ; by 
growth these take on the form and size of the adult indi- 
viduals. 

§ II. Class (Edogonie^. 

327. — The plants constituting this well-marked class are 
composed of articulated, simple, or branched filaments, 
which are attached to sticks, stones, earth, or other objects 
by root-like projections of the basal cells. The chlorophyll 
in the cells is always dense and uniform. They inhabit 
ponds and slow streams, and form green masses, which fringe 
the sticks and other objects in the water. 

328. — The QEdogoniese are interesting for the well-marked 
examples they afford of the intercalary growth of cells. It 
is commonly the case that in any filament at one or two 
points there may be seen near one end of a cell a number 
of transverse parallel lines, which in profile have the appear- 
ance of as many caps slipped into one another (6', Fig. 10, 
page 22) ; these are the results of several extensions of the 
filaments by intercalary growth. The process is as follows : 
in a cell, a little below its upper wall, a growtn inward from 
the surface of the wall takes place in such a way as to form 
a cylindrical ring {A, f, Fig. 10); after a time the cell-wall 
splits circularly from the outside to the centre of the circu- 
lar cylinder (/), and the two parts of the cell then retreat 
from each other, united only by the straightened out cylin- 
der {B, z, Fig. 10); this new part elongates and the procesp 
"s repeated, finally giving rise to the series of caps first men- 
tioned (C, c, Fig. 10), and, in conjunction with cell-division 
resulting in a considerable elongation of the filaments. 



(EBOQONIEJE. 



247 



320. — The asexual reproduction of (Edogonieae is as curl 
ous as the growth of its cells, just described. During the 
early and active growth of the 
plants the protoplasmic contents of 
certain cells in a filament become 
detached from their walls, and upon 
the splitting of the latter the now 
rounded protoplasm escapes as a 
.large zoospore (Fig. 166, A and 
E) ; it is oval in shape, and provid- 
ed with a crown of cilia about its 
smaller hyaline end, by means of 
which it swims rapidly hither and 
thither in the water (Fig. 166, (7). 
After a time it comes to rest, 
clothes itself with a cell-wall, and 
sends out from its smaller end root- 
like prolongations (Fig. 166, i)), 
which attach it to some object ; it 
now elongates, and at length forms 
partitions, taking on eventually the 
form of the adult filament. It 
sometimes happens that before the 
new plant resulting from the 
growth of a zoospore has formed its 
first partition, the protoplasm sep- 
arates from its wall and again aban- 
dons it, to be for a time a zoospore 
(Fig. 166, E\ This method of 
formation of zoospores is what 
Braun called Eejuvenescence. (See 
p. 42.) 

330. — The sexual reproduction 
of the plants of this class is in 




Fig. 166. — Asexual reproduc- 
tion of (Edogonium. A, fracture 
of a filament and escape of the 
protoplasm of the broken ceil ; 
the protoplasm in the whole cell 
below is seen to be somewhai 
withdrawn from the cell-wall, 
preparatory to escaping. B, es- 
cape of protoplasm and formatiou 
of a zoospore; the hyaline por- 
tion of the latter is seen to be lat- 
eral. G, a ciliated and swimming 
zoospore, the hyaline portion now 

many respects closely allied to that anT sending ' ou't'^roo^iike pro- 
of SphcBroplea, The female organs ^^ri^'J^omifpTaif cS-ed™of 
are in all cases developed in essen- etaySr'^^'aS!-!^?^!" 
tially the same way, but the male ^®^°^- 
organs present a considerable diversity. The female organ 



i^48 



BOTANY. 



consists of a rounded oospliere situated within a cavity — tlie 
oogonium ; it is developed from one of the cells (sometimes 

two) of the filament 
by a condensing 
and rounding off 
of the protoplas- 
mic contents; when 
the oosphere is ful- 
ly formed, an open-- 
ing is formed in 
the oogonium-wall 
for the ingress of 
the sioermatozoids 
(A and B, Fig. 
167). One or more 
spermatozoids are 
produced in each of 
certain small cells 
which are formed 
from the large ones 
by a process of 
simple fission ; in 
shape they resem- 
ble the zoospores 
mentioned above — 
that is, they are 
oval and provided 
with a croAvn of 
vibratile cilia on 
their smaller ex- 
tremity (D, z, z^ 
Fig. 167). Upon 
escaping into the 
water, which is ren- 
dered possible by 
a splitting of the 
wall of the mother- 
cell, they swim about vigorously, and eventually make their 
way through the opening in the oogonium, and then burj 




l'')g. 167—^, middle part of a sexual filament of (Edo- 
gonium ciliatum {Andiogynia of Wood), with male cells 
above at m; og, oogonia (fertilized); m, dwarf male 
plants attached to the side of the oogonia, the sperma- 
tozoids already discharged. X 250. £, oogonium, og, 
at the moment of fertilization ,• o. the oos^phere ; s, the 
spermatozoidlbrcing its way into the oosphere; ?«. the 
dwarf male plant. G, ripe oospore. Z>, (Edogonium 
gemelliparum {Pringsheimia of Wood), part of the male 
filament, with sperriiatozoids, z, issuing from the cells. 
E, part of a branch of Bulboehoete intermedia, with oogo- 
nia, the uppermost containing an oospore, the middle 
one with an oospore escaping, the lower empty. F, four 
zoospores resulting from an oospore of Bulboc/icete. O, 
eoospore come to rest and germinating. — After Prings- 
heim. 






t 



(EDOGONIEJS. 249 

themselves in the substance of the oosphere {B, z, Fig. 167). 
After fertilization the oosphere becomes covered with a thick 
and colored (brown or red) coat, and it then becomes an 
oospore {G, Fig. 167). 

331. — In certain cases the cells which prodnce the sper- 
matozoids occur on the same filaments which produce 
oogonia also ; this is the monoecious type. In other cases one 
of the ordinary cells of the filament which bears oogonia be- 
comes divided by simple fission into two or more cells ; the 
protoplasm in each of these new cells condenses into an 
ovate mass, which by a rupture of the cell-wall is set free as 
a motile body resembling a small zoospore, and, like it, pro- 
vided wath acroAvn of vibrating cilia; this is the andros2:)ore. 
After swimming about for some time, it comes to rest upon, 
or near to, an oogonium, and attaches itself by root-like pro- 
jections, exactly as in the case of the growth of true zoo- 
spores ; the result of the growth of the androspore is the pro- 
duction of a miniature plant comj)osed of three or four cells 
{A, m, m, and B, m, Fig. 167). The upper cells of these 
little plants develop sj^ermatozoids, and hence the plants are 
called dwarf males. This is the so-called gynandrous type 
^A and B, Fig. 167). In a third class of cases, the ordinary 
plant filaments are of two kinds, the one producing sperma- 
tozoids only, and the other only oogonia ; this is the dioecious 
type [D, Fig. 167). 

332. — After a period of rest the oospore germinates by 
rupturing its thick coat, and permitting the escape of the 
contents, enclosed in a thin envelope ; by this time the pro- 
toplasm has divided into four portions, which take on an 
oval form, and develop a crown of cilia (F, Fig. 167). They 
soon escape from the investing membrane, and after a brief 
period of activity grovf into an ordinary filament in exactly 
the same manner as the zoospores. 

(a) It will be unnecessary in this place to fully discuss the arrange- 
ment of the genera belonging to this cFass ; they probably may be all 
brought within the limits of one order coextensive with the class. 
Wood has separated* two sub-families (= sub-orders), which differ in 

* " A Contribution to the History of the Fresh-water Algae of the 
United States," by H. C. Wood, 1872. 



250 BOTANY. 

tlie filaments in tlie one case (Bulbochcete) being branched and terminated 
with set«, while in the other case {(Edogonium and its allies) the fila- 
ments are not branched, and are destitute of true setae. 

ip) The old genus (Edogonium is divided by Wood into three new 
genera, as follows : 

Monoecious : autheridia and oogonia upon the same individual — 

(Edogonium. 
Dioecious : antheridia and oogonia arising upon distinct individuals 

— Pringsheimia. 
Gynandrous : antheridia upon dwarf plants, growing attached to 
the female plant — Androgynia. 
Wolle records thirteen species of the first, thirteen of the second, 
and twenty-six of the third of the foregoing divisions in the United 
States. He does not, however, consider these divisions as having 
generic rank. ("Fresh-water Algne of the United States," Vol. I. 
p. 66.) 

(c) The genus Bulhoclmte includes gynandrous species, of which 
there are sixteen in the United States. 



§ III. Class Cgeloblaste^. 

333.— In the plants of this class the protoplasm is con- 
tinuous throughout the vegetative organs of the plant, and 
is not divided into cells. Only the reproductive organs are 
separated by partitions. They may hence be siDoken of as 
unicellular, although they often attain a considerable length 
and are frequently much branched. 

The other characters of the group will be best understood 
from a study of some of the jDlants included in it. Many of 
them are chlorophyll-bearing plants, living in brooks and 
streams, while others are destitute of chlorophyll, and are 
saprophytes, living upon decaying animal or yegetable matter, 
or are parasites, living upon the living tissues of the higher 
plants. 

334. — The genus Vauclieria may be taken as a represen- 
tative of the chloro|)hyll-bjparing members of this class. It 
is a filamentous alga growing in water or on damp earth, and 
forming dark green tufts. Each plant consists of long, 
branching, thick-walled tubes, which have a rather large 
diameter ; they are attached to the earth, or to sticks or 



CCELOBLAISTEjS. 



251 



other objects, by root-like processes (w, Fig. 168). The 
protoplasmic contents of the tubes, which are destitute of a 
nucleus, consist of a thick green layer upon the inner sur- 
face of the wall, leaving the centre of the tubes open for the 
more watery portions. 

335.— The asexual reproduction of Vaucheria presents 
some considerable variations ; it consists essentially of a 
spontaneous separation of a portion of the protoplasm of the 
parent plant. In some species this takes place by the sepa- 




Fig. 168.— Vaucheria sessilis. A, end of a branch, with escape of a zoospore, sp. B, 
zoospore in its renting stage, after the disappearance of its cilia. C, the same, germi- 
nating. Z>, the same, further advanced. E, much later stage of germination ; sp, the 
zoospore; w the root-liki' processes (rhizoids). F, fertile plant ; og, og, oogonia fer- 
tilized ; A, an old antheridium. x 30 — After Sachs. 

ration of swollen lateral branches, which then send out fila- 
ments ; in other species the protoplasm in the swollen lateral 
branch becomes separated from that in the general cavity of 
the plant by a septum, and it afterward condenses into a 
rounded mass and acquires a wall of its own ; it is set free 
by the decomposition of the old surrounding wall, and it 
germinates by sending out one or two tubes, which grow 



252 



BOTANY. 



directly into new plants. In still otlier species the spore 
forms as in the last case, but there is a dehiscence of the sur- 
rounding wall wliich permits the spore to slip out ; it begins 
to germinate soon. In some species, instead of forming a 
spore, the naked protoplasm in the swollen branches, after 
condensing somewhat, escapes into the water through a 
fissure in the cell-wall, and becomes a zoospore [A, Fig. 
168) ; it is covered throughout its whole surface with delicate 
vibratile cilia, by means of which it moves through the 
water (Fig. 169). After a short period of activity the zoo- 
spores come to rest, their cilia disappear, and a wall of cellu- 
lose is formed {B, Fig. 168) ; in this condi- 
tion (the zoogonidium) they remain for some 
hours, when they begin to germinate by 
sending out one or two tubes {C, D, Fig. 
168) ; the root-like organs grow either direct- 
ly from the zoogonidium {F, Fig. 168), or 
from one of the tubes {E, Fig. 168). 

336. — Sexual reproduction takes place in 
lateral branches also. Both antheridia and 
oogonia develop as lateral protuberances upon 
the main stem {og, og, Ji, Fig. 168). They 
originate as diverticula of the principal cavity 
(A, og, li, Fig. 170) ; these develop on the one 
hand into male organs, and on the other 
preparation, after into female orgRus. The male organ is long 
uiger. ^^^ rather narrow, and soon much curved 

{B, a, Fig. 170) ; its upj^er portion becomes cut off by a 
partition, and in it very small bi-ciliate spermatozoids (i>. 
Fig. 170) are developed in great numbers. The female or- 
gan is short and ovoid in outline, and usually stands near 
the male organs. In it a partition forms near its point of 
union with the main stem ; the upper portion becomes an 
oogonium, and its protoplasm condenses into a rounded 
body, the oosphere (C'and E, Fig. 170) ; at this time the 
wall of the oogonium opens, and permits the entrance of the 
spermatozoids which were set free by the rupture of the 
antheridium-wall. ITpou 'oming into contact with the 
oosphere the spermatozoids mingle with it and disappear ; the 




Fig. 169.— Section 
at right angles to 
the sui'Face of a zo- 
ospore of Vati>che- 
liasessilis. a, ecto- 
plasm bearing the 
cilia ; b, eudoplasm. 
X 600.— Osmic acid 



CWLOBLASTE^. 



253 



oospliere immediatjlj begins to secrete a wall of cellulose 
about itself, and it thus becomes an oospore {F, Fig. 170). 
According to Pringslieim, tlie oospore remains for three 
months in a resting state before germinating ; in the latter 
process the outer coat of the spore splits, and through the 
opening a tube grows out which eventually assumes the form 
and dimensions of the full-grown plant. 




Fig. 170. — Sexual organs of Vmicheria sessilis. J., heginning of the formation of 
the oogoninni (07) and antheiilinm (h) upon the branch h. B. later stage of the 
same, the antheridinm (a) now separated from the main branch (b) by a transverse par- 
tition. C an open oogonium expelling a drop of protoplasm, sZ. D, suei-matozoids. Fj, 
spermatozoids collected at the mouth of the oogonium. F, the antheridinm, a. col- 
lapsed after the escape of the spermatozoids ; os]-), the oospore. X about 100, except 
Z>, which is much more.— C, D. after Pringsheim, the others after Sachs. 

{a) The formation of zoospores begins in the nig-ht, they escape in 
the morning, an.l the night following they germinate. 

(6) The formation of sexual organs begins in the evening, and is 
completed the next morning ; fertilization takes place during the day 
(from 10 A.M. to 4 p.m.). 

(c) Good specimens of Vaucheria may be found clothing the boggy 
ground about many springs. The bright green mats may be trans- 
ferred to the aquarium for the study of zoospores ; but for the sexual 
organs the dingy and dirty looking specimens must be collected. 



354 BOTANY, 

(d) The genus Vauclieria may be taken as the type of a group, the 
VaucheriacecB, but whether it is entitled to rank as an order instead 
of a family cannot be decided in this place. Allied to Vaucheria are 
(Jaulerpa, Halimeda, etc., but their exact position is as yet problematical. 
{e) Thirteen species of Vaucheria occur in the fresh waters of the 
United States, one of the most common being V. sessilis, which 
occurs everywhere in brooks and springs. 

(/) Caulerpitea cacPAdes is the oldest known fossil species of this 
class. It occurs in the Silurian : other species have been detected in 
the Devonian and Tertiary. Caulerpa extends from the Tertiary to 
the present. 

337.— Order Saprolegniacese. The plants of this order 
are saprophytes or parasites, more frequently the latter ; they 
are colorless, and generally are to be found in the water or in 
connection with moist tissues. The plant-body is greatly 
elongated and branched, and all its vegetative portion is 
continuous — i.e., unicellular ; the reproductive portions only 
are separated from the rest of the plant-body by partitions. 

338. — The reproduction is very much the same as in 
Vauclieria,^ and, as. in that genus, is of two kinds — asexual 
and sexual. The asexual reproduction may be briefly de- 
scribed as follows : the proto^Dlasm in the end of a branch 
becomes somewhat condensed, a septum forms, cutting off 
this portion from the remainder of the filament, and the 
whole of its contents becomes converted by internal cell- 
division into zoospores provided with one or two cilia 
(Fig. 171, 1). These soon escape from a fissure in the wall 
and are active for a few minutes (3-4), after which they 
come to rest and their cilia disappear (2 and 3, Fig. 171). 
In one or two hours they germinate by sending out a filament 
(4, Fig. 171), from which a new plant is quickly produced.* 

339. — The sexual organs bear a close resemblance to those 
of Vaucheina. The oogonia are spherical, or nearly so (in 
most of the species), and contain from two to many oospheres, 
which are fertilized by means of antheridia, which usually 
develop as lateral branches just below the oogonia. In 

* The student is referred to an article, "Observations on Several 
Forms of Ssprolegniege," by F. B. Hine, in American Quarterly Micro- 
scopical Journal, 1878, p. 18, from which some of the above facts are 
taken, and the accompanying figures adapted. 



SAPOLEGNIACEJEJ. 



255 



some species the antlieridia and oogonia are upon the same 
plants, and in such cases the fertilization takes place by the 




Fig. 171.— 1, end of filament of Saprolegnia, witli zoospores (swarm- 
ing ; 2, zoospores of the same at rest ; 3, the same more enlarged ; 4, the same, 
germinating: 5, a portion of a filament of Achlna, bearing sexual organs, x 120 ; 6, 
first stage in th i development of sexual organs of AcJdya ; 7, 8, 9, succeeding stages ; 
10, sexual organs of 5, more enlarged, showing the antheridia, and the nearly ripe 
oogonium, with its contained oospores.— Adapted from Hine. 

direct contact of the antheridium and the passage of its 
contents into the oogonium by means of a tubular process 



256 



BOTANY. 



f^'om the former ; in otlier sjoecies the plants are dioecious, 
and in them the antheridia produce motile spermatozoids^ b} 
means of which the fertilization is effected. After fertilization 
each oosphere becomes covered with a wall of cellulose and 
is thus transformed into an oospore. 

340. — The development of the sexual organs of AcJilya, 
one of the genera of this order, is shown in Fig. 171, 6 to 
10 ; at first there is a small j)ullulation upon the side of a 
filament, as at 6 ; this soon extends into a bag-like projec- 
tion (7), which is readily seen to be a young oogonium; 
it continues to enlarge, while its protoplasm becomes more 

dense,, and at its narrower 
part a second pullulation 
forms (frequently two), as 
shown at 8 ; when the larger 
part has enlarged somewhat 
more and become rounded, a 
partition separates it from 
the remainder of the filament^, 
and from the young anther- 
idium, as shown at 9 ; the 
protoplasm in the oogonium 
forms several round masses — ■ 
the oospheres — and by this 
time the terminal portion of 
the antheridium is cut off by 
a partition. In the monoe^ 
cious species a tube is formed by the closely applied anther- 
idium, which penetrates into the oogonium through open- 
ings in it formed by the absorption of portions of its wall 
and comes in contact with one of the oospheres (Fig. 172). 

341. — In some cases, instead of the oogonia developing 
in the way described above, they are formed in the terminal 
part of a filament by one or more partitions arising in it ; 
such oogonia are cylindrical or barrel-shaped, and sometimes 
several of them stand upon one another. The antheridia in 
the species which have such oogonia are developed from 
below the partition which cuts ofi: the oogonium, and when 
there are several superimposed oogonia it actually happens 




Fig. 172. — F. rt.liziitionof the oospheres 
in AcMya raceniosa. Each oogonium 
contains two oospheres. Magnified. — 
After Cornu. 



SAP BO LEG mA CEJE. 



25? 



fcliat the antlieridia which fertilize one oogonium grow out 
of the oogonium lying immediately beneath.* In this case 
it appears that the terminal oogonium is formed first, and 
that the antheridia, in each case, grow out from what is yet 
a part of the whole filament, and that it is only subsequently 
to the formation of antheridia that an oogonium is formed 
out of that part of the filament out of which they grew. In 
the accompanying diagram (Fig. 173) the 
oogonium a is fertilized by antheridia 
which grew out of that portion of the 
filament which subsequently became cut 
off as oogonium h, which in turn is fer- 
tilized by antheridia from below it, and so 
on to d, which receives its antheridia 
from what still remains as |)art of the fil- 
ament. Each oogonium is seen to be 
younger than the one aboye it — in other 
words, the oogonia are developed from 
the top of the filament downward. 

The oospores of Saprolegniaceae possess, 
when mature, a thick integument, which 
is double — that is, formed of an outer 
thicker coat (epi spore) and an inner thin- 
ner one (endospore). After a considerable 
period of repose the oospores germinate 
by sending out a tube, f 

The Saprolegniacese have been but little stud- 
ied in this country, although they may be read- 
ily obtained. They grow quickly upon dead 
fishes, crayfishes, flies, etc., when placed in tanks 
of water, and may often be seen attached para- 
sitically to young living fishes in aquaria. They 
are often so abundant in the breeding-houses of 
fishes as to cause great losses. In some of the rivers in England du 




Fig. ITS.— Diagram il- 
lustrating the formation 
of the sexual organs 
and the fertilization of 
SaproUgnia androgyna. 
a, the oldest oogonium, 
which is fertilized by 
the antheridia grown 
from below ; b, the next 
oldest oogonium ; c, 
younger oogonium, with 
the oospheres not yet 
fully formed ; c?, young- 
est oogonium ; the lat- 
ter will be fertilized by 
the antheridia which 
grow out from the upjier 
end of the filament be- 
low. 



* The student should consult an article on " Two New Species of 
Saprolegnieae," etc., in Qr. Jour. Mic. Science, 1867, p 121, in which 
figures and a description of such a form as that above referred to are 
given, 

f See De Bary's " Morphologic und Physiologie der Pilze," etc., 1866, 
p. 155, for an account of the sexual reproduction of Saprolegniaceae^ 






258 



BOTANY. 



ing the year 1878, and for a year or two previous to that date, large 
numbers of salmon and other kinds of fish were destroyed by one of the 
common species, Saprolegrda ferax.* 

342.— Order Peronosporese. The plants of this order 
live parasitically in the interior of higher plants. They are 
composed of long branching tubes, whose cavities are con- 
tinuous throughout. They grow between the cells of their 
hosts, and draw nourishment from them by means of pecu- 




FiG. 174. 

Fig. 174.— A vegetative hypha, m, m, of Peronospora calotheca from the tissue of 
Asperula sativa. The two cells between z z are filled with the long branching haus- 
toria from the hypha m, m. X 390.— After De Bary. 

Fig. 175.— Conidia-bearing hyphae of Peronospora infestans. a, formation of the 
fir.«t conidia upon the ends of slender pedicels ; b, the formation of the second and 
third ( onidia ; the pedicel is proliferous from the base of each coiiidium after it is 
formed, and thus the conidia, which are actually terminal, come to appear lateral. 
X 200.— After De Bary. 



liaiiy formed lateral branches {Jiaustoria)^ which thrust 
themselves through their walls (Fig. 174, and Fig. 176, A, 7i). 
The vegetative growth is entirely within the host, and also 



and a translation in " Grevillea," Vol. I., p. 117. See also Prings- 
heim's " Jahrbucher fiir WissenscliaftlicheBotanik," Vol. IX., p. 289, 
and Max Cornu, in " Annales des Sciences Naturelles," 5e ser., torn. 
XV. 

* See a description by W. G. Smith in " Grevillea," Vol. VI., 1878, 
p. 152. 



PEUONOSPORM. 



259 



tlie sexual organs ; tlie asexual reproductive organs, on tlie 
contrary, are on the surface of the host. 

343. — The asexual reproduction takes place in the genus 




Fig. Vt^.—Cystopiis candidus. A, branch of mycelium,/, growing at the apex, ^, 
and giving off haustoria, h, into the cells of the pith of Lejndium sativum. B, co- 
nidia-beanng portions of the mycelimn, with conidia in rows. C, a conidium with 
its protoplasm divided. Z>, contents of conidia escaping as swarm-spores (zoospores). 
E, swarm-spores (zoospores), with cilia. F, germinating swarm-spores. G, two swarm- 
spores, sp, germinating on a stoma and penetrating it. //. a swarm-spore, sp, of the 
potato disease {Peronospora infestans) penetrating the epidermis of the potato stem ; 
e, i, epidermis cells, x 400.— After De Bary. 

Peronospora by the mycelium inside the host producing 
branches, which protrude through the stomata into the air ; 
here their tips become enlarged^ and finally separated by par- 
titions from the remaining parts of the hyphae, thus forming 



2G0 



BOTANY. 



the conidia (Fig. 175). In tlie different species there are 
considerable variations in the size and shape of the conidia, 
and the mode of branching of tlie conidial hyphse, and upon 
these many siDCcific characters are based. 

344. — In the genus Gy storms the formation of conidia is 
shglitlj different. The conidial hyphse multiply greatly at 
certain points beneath the epidermis of the host, and there 
l^roduce conidia by successive constrictions {B, Fig. 176). 
The conidia remain in loose connection, and form monilif orm 
rows, in which the uppermost conidium is the oldest ; some- 
times six or more conidia may be seen attached to each other 
in this way, but generally the upper ones soon fall away. 
When the epidermis of the host ruptures, the conidia appear 

as a powdery mass, 
which may be blown 
away by the feeblest 
movement of the air. 

345. — The germina- 
tion of conidia presents 
two modes ; in some 
species of the genus 

Fig. 177.— Germination of the conidia of Perono- ^ , , 
spora infestans. a, conidium after lying for some JrerOnOSpora tUC Cen- 
time in water, the contents divided ; ^>, the rupture J.Q^^J_„ _-p J_l^- <^r^■n^/^^^^Tr. 
of the conidium and the escape of the parts as t*^-iiLfe ui ine ouiiiUiuni, 
swarm-spores (zoospores); c, swarm-spores, with -rtr]-, p-,-, y<\^0(^(\ nnrlpr tbf^ 
cilia ;«;, swarm-spores after coming to rest, m va- "uexi jjiciueu uiiuci uiit^ 
rious stages of germination. X 390.— After DeBary. proper COUditionS of 

moisture and temperature, become transformed into many 
bi-ciliate swarm-spores {a, J, and c, Fig. 177). These are 
active for a time, after which they come to rest, their cilia 
disappear, and a germinating tube is sent out from each 
(d, Fig. 177), which, if properly situated, enters a stoma, 
and in the interior of its host gives rise to a system of vege- 
tating hyphge ; in other cases it perforates the ej)idermis cell- 
walls and thus passes into the interior of its host {Hy Fig. 
176). In other species of Peronosj^ora the conidium does not 
break up into swarm-spores, but gives rise directly to a ger- 
minating filament. In all the species of the genus Cystopus^ 
the conidia first give rise to swarm-spores ( C, D, E, F, G^ 
Fig. 176), in the manner described above for Peronosporao 




PEBONOSPOBE^. 



261 



346. — lu the sexual reproduction,* wliicli, as aboye stated, 
always takes place in the intercellular spaces of the host, 
lateral branches of two kinds arise upon the hyphae ; those 
of the one kind, the young oogonia, become greatly thickened 





Fig. 178.— The sexual organs and fertilization of Peronospora Alsinearum. «, 
youngest stage ; o, young oogonium ; w, young antheridium ; h, the same somewhat 
later ; the antheridium is beginning to thrust its beak-like process (fertilizing tube) 
into the oogonium ; c, the same at a still later stage— the fertilizing tube has reached 
the oosphere. x 350.— Alter De Bary. 

in diameter, and finally assume a globular shape ; their 
highly granular protoplasm becomes condensed, and finally 
separated from that of the remainder of the filament by a 
transverse septum at the base of each oogonium {a, Fig. 178), 
The other branches, the young anthe- 
ridia, which arise upon the same fila- 
ments as the oogonia and near to 
them, or upon other filaments which 
are in proximity to the oogonia-bear- 
ing ones, become elongated and club- 
shaped ; their protoplasm (also gran- 
ular) becomes condensed in their up- 
per portions, which are soon separated 
from the rest of the filament by a 
transverse partition in each case (a, 
Fig. 178). At this stage the an- 
theridia become applied to the oogonia, and in each of 
the latter the protoplasm has still further condensed and 

* Consult De Bary's " Morpliologie uud Pliysioloofie der Pilze," etc., 
pp. 158-159, a translation of wkicli appeared in " Grevillea/' 1873, p. 
150. 




Fig 179.— Oogonium of Pe- 
roiio-pora, with its contained 
oosphere; at the left is the 
antheridium, which has pene- 
trated the oogonium and 
brought its fertilizing tube 
into contact with the oo- 
sphere. Much magnified.— 
After De Bary, 



202 



BOTANY. 



rounded into an oospliere. Each antliendiuin noAv devel- 
ops a tubular beak-like process, which penetrates the oogo- 
nium {h, Fig. 178), and finally reaches the oospore (c. Fig. 
178, and Fig. 179). It aj)pears that the contents of the an- 




Fig. 180.— Cysfopvs candidus. A, Tnyceliiim, with yonng oogonia, og. B, oogoni- 
um, og ; 08, oospore ; an, antheridium. C, mature oogonium, 0.17, with oospore, os ; 
at the left is the remnant of the antheridium. D, mature oospore seen in section. £^, 
beginning of germination of oospore, the endospore i with its contents escaping 
througli a rent in the epispore (or exospore). F, the endospore i filled with swarm- 
epores (zoospores) resting on the empty epispore. G, swarm-spores (zoospores), each 
with two cilia, x 400.— After De Bary. 



theridium pass into the oosphere, as in a short time the 
former is found to be empty, while the latter becomes enyel- 
oped in a cell-wall, and thus becomes an oospore. In the 
process of fertilization there are no spermatozoids, and the 






PERONOSPOBEJEJ. 263 

process is comparable to that which takes place among the 
monoecious Saprolegniacese. The wall of the oospore be- 
comes differentiated into two or more layers (as, in fact, is 
usual in resting spores), the outer of which (the epispore) is 
thick, hard, rough, and dark colored, while the inner (the 
endospore) is thin and transparent (C, D, E, F, Fig. 180). 

347. — In their sexual reproduction the species of the genus 
Cystopus agree with those of Peronospora above described. 
The various stages are shown in Fig. 180. 

348. — The germination of the oospores takes place in some 
species of the genus Peronospora by the formation of a ger- 
minating tube, which soon gives rise to a mycelium. Ii 
Cystopus, however, the oospore swells, and by the bursting 
of the epispore the endospore escapes as a loose bladder sur 
rounding the protoplasm, which has by this time become di. 
vided into a large number of naked masses of protoplasm 
{E, F, Fig. 180) ; by the bursting of the surrounding mem- 
brane, these bodies are set free as bi-ciliate swarm-spores ( G, 
Fig. 180), which, after a short period of activity, come to 
rest, and germinate in exactly the same way as those derived 
from the conidia. In some species of Peronospora it appears 
that swarm-spores are developed as in Cystopus, and it ap- 
pears from the observations of W. G. Smith, that in the potato 
fungus {Peronospora infestans') some of the oospores pro- 
duce swarm-spores, while others send out a germinating 
tube. * 

349. — But little is known regarding the time, as well as 
the mode of germination of the oospores, but from those ob- 
served it is probable that it takes place after a period of rest 
extending from autumn to spring. This is known to be the 
case in some species of Cystopus, in which the oospores pass 
the winter in the rotting tissues of its hosts. 



* See a paper " On the Germination of the Resting Spores of Perono- 
spora Infestans," by Worthington G, Smith, in Oardeners' Ghronide, 
July, 1876, and reprinted in " Grevillea," 1876, p. 18. He found that the 
oospores which germinated first produced swarm-spores like those of 
Giistopus, while the later ones " protruded a thick and generally jointed 
thread." In his account figures of both modes are given. 



2G4: BOTANY. 

(a) The plants of this order are easily obtained, and so far as their 
Btnicture is concerned, are easily studied. Their development is, how- 
evei, much more difficult to follow, and in some species it has thus far 
battled the most skilled botanists. The two genera Peronospora and 
Ct/stopus are distinguished by their conidia, which in the first are ter- 
minal and siugle upon branches of the aerial hyphae (Fig. 175), while 
in the second they are in moniliform rows upon hyplige which burst 
through the epidermis of the host {B, Fij?, 176). 

(6) Several species of Peronospora are very easily obtained. P. mti- 
cola, the American grape mildew, is common on the leaves and young- 
shoots of the grape ; from it may be obtained in midsummer an abun- 
dance of conidia and conidial hyphae, and in autumn (October) the 
oospores may be found in abundance in the dried and shrivelled parts of 
the affected leaves.* P. parasitica is? common in spring and early sum- 
mer, on Cruciferae, especially on Lepidium, Capsella, Draha, etc., fre- 
quently clothing the leaves with a white, frost-like down. P. infestans, 
the potato fungus, is common in many parts of the country on the 
leaves and stems of the potato, sometimes causing great injury by de- 
stroying the leaves, stems, and even the tubers. Other species occur 
on Eupatoriam, Bidens, Ambrosia, Impatiens, Potentilla, Anemone, 
etc. 

(c) The species of Gystopus which are most common are C. candidus, 
which may be found in the spring and summer as white, blister-like 
blotches on the leaves of Capsella and other Cruciferae ; and C. Bliti com- 
mon on Portulaca oleracea and species of Amarantus in summer and 
autumn ; the latter is an excellent species to study, as its oospores are 
very easily found, especially in the stems of Portulaca. 

(d) In preparing specimens for the study of the sexual organs, small 
portions of the tissues containing them should be boiled for a minute 
or so in a solution of potash, and then, while the preparation is hot, a 
considerable quantity of acetic acid should be added ; the effervescence 
which follows separates the softened tissues so that but little difficulty 
is experienced in isolating large portions of the mycelium with oogonia 
and antheridia. It frequently happens that the parts are rendered 
more distinct by the addition of iodine to the specimen after mounting 

§ IV. Class Fucace^. 

350. — The plants of this class, composed of marine spe- 
cies, present, in most cases, a development of the plant-body 
which is unusually perfect for the Thallophytes. In many 

* For the best account of this fungus see a paper " On the American 
Grape-vine Mildew," by Professor W. G. Farlow, in Bulletin of the 
Bussey Institution, Yo\. I., p. 415. Several other species are also briefly 
described. 



FUCACEJP]. 265 

cases there is a differentiation of the thaUus into parts which 
have a considerable resemblance to roots, stems, and leaves ; 
and in size they approach, and, in some cases, equal or exceed 
the larger Phanerogams. Their tissues, too, show a much 
higher degree of differentiation than is common in Thallo- 
phvtes ; the cells are arranged in cell-masses, and these are 
differentiated into several varieties of parenchyma, approach- 
ing, in some instances, to the condition which prevails in 
the Bryophytes ; the outer tissues are composed of small and 
closely crowded cells, which form a dense, and, in some cases, 
a hard mass ; the interior tissues are generally looser, and 
are for the most part composed of elongated cells so joined 
as to leave large intercellular spaces. 

351. — With the foregoing there is found in the higher 
genera a marked differentiation of portions of the plant- 
body into general reproductive organs, analogous to the 
floral branches of higher plants. The sexual organs are 
found upon modified branches, which differ more or less in 
shape and appearance from the ordinary ones. This differ- 
entiation into vegetative and reproductive parts is an impor- 
tant and significant feature in the plant-body, indicating a 
decided advance over all the previous groups of Thallo- 
phytes. 

In their greater duration many of the Fucacese are in 
marked contrast to other Thallophytes, which are generally 
short-lived. They are, for the most part, of considerable 
size, rivalling, in some cases, even the larger Phanerogams. 
They grow principally between and a little beyond the tide- 
marks, and furnish the great bulk of the shore vegetation. 

352. — The reproduction of the higher Fucaceae is sexual 
only ; but in some algae which appear to be nearly allied 
(Phseosporeae) asexual zoospores are known. In Fucns 
the sexual organs are found in the thickened ends of the 
lateral branches of the thallus {A, Fig. 181). They occur 
on the walls of hollows termed conceptacles, which are 
spherical, with a small opening at the top (B, Fig. 181). 
The conceptacles are at first portions of the general surface, 
w^hich afterward become depressions which are walled in 
and overgrown by the surrounding tissues ; they are thus to 



)l(j(j 



BOTANY. 






be still regarded as portions of the general surface, and the 
cells which form the inner surface of the conceptacles con- 
stitute a continuation of the epidermal tissue of the thallus. 
353. — The walls of the conceptacles are clothed with 
pointed hairs, which in some species project through the 




^^' 



'>^%J^ 



Fig. 181.— Fueus platycai^ms. A, end of a portion of thallus ; /,/, conceptacles in 
fertile branchlets. £, vertical section through a conceptacle ; a, hairs projecting 
from the month : b, cavity of conceptacle nearly tilled witli hairs ; c, oogonia ; e, an- 
theridia ; d, epidermal tissue of thallus.— After Thuret. 

opening, and among these are found the sexual organs, 
which are themselyes, as Sachs has pointed out, modified 
hairs. Some of the species are monoecious, while others are 
dioecious. In the monoecious species the antheridia and 
oogonia occupy the same conceptacle {B, Fig. 181) ; the 
antheridia are produced as lateral branches of modified hairs 



FUCACEJE. 



267 



{A, Fig. 182) ; eacli antlieridinm is a thin-walled cell, whose 
protoplasm breaks up into" a large number of bi-ciliate sper- 
matozoids, which escape by the rupture of the surrounding wall 
(B, Fig. 182). Before rupturing, however, the antheridia 
detach themselves and float in the water with their contained 
spermatozoids. 

354. — The oogonia are globular or ovoid short-stalked 
bodies, which develop from papillae on the wall of the con- 
ceptacle. As each papilla elongates, it becomes divided into 




Fig. W>2,—Fucus vesiculosus. A, branched hair bearing antheridia, a. B, sperma- 
tozoids. 7., og, oogonium, with contents divided into eight parts ; j), paraphyseB, or 
smTounding hairs. //., commencement of tlie escape of tlie oospheres— the outer 
wall, a, of the oogonium has burst, the inner, i, is ready to open. ///., oosphere es- 
caped, and surrounded by f-permatozoids ; IK, F., germination of the oospore. £ 
X 330, ail the rest IGO. -After Thuret. 



a basal and an apical poi'tion by a transverse partition ; the 
apical part enlarges, and (in the genus under consideration) 
its protoplasm divides into eight portions (/, Fig. 182), 
which eventually become spherical ; it is thus an oogonium 
containing eight oospheres. The oospheres escape from the 
oogonium surrounded by an investing membrane, which floats 
out through the opening of the conceptacle, where it finally 
ruptures aud sets the oospheres free (//, Fig. 182). The 
spermatozoids and oospheres are liberated at about the same 



2G8 BOTANY. 

time, and tlie former gatlier around the inactive oospheres 
in great numbers, and by the vigor of tlieir movements 
sometimes actually give them a rotatory motion (///, Fig. 
182). The result of the coming together of the spermato- 
zoids and the oospheres is the fertilization of the latter, and 
their transformation into oospores by the secretion of a wall 
of cellulose on each one. There is thus seen to be a close 
similarity between the fertilization of Fucus and of other 
Oosporeae ; particularly does it call to mind the sexual pro- 
cess in Volvox and its allies. When, however, the sexual 
organs proper, and their accessory organs, the conceptacles, 
are taken into the account, the relationship of Fucus to Volvox 
is seen to be much less than it appears to be at first sight. 

355. — The development of the oospore takes place at 
once ; it lengthens and nndergoes division into numerous 
cells, and at the same time it elongates below into root-like 
processes, which serve to hold fast the new plant (F, IV, 
Fig. 182). There is a gap in our knowledge of the life- 
history of these plants, extending from the young th alius to 
the fertile plant ; probably when that is filled some plants 
now supposed to be distinct will be found to be forms or 
stages of these. 

{a) The principal genera of Fucacece are Fucus and Sargassum. Of 
the first, F. nodosus, F. furcatus, and F. msiculosus are the most 
common species on our Eastern coast, the latter also occurs on the 
Pacific coast; both are known as Rock- weeds. Sargassum Dulgare is 
common on the Atlantic coast ; S. hacciferuin, the Gulf-weed, is 
found in the warmer parts of the several oceans, and in mid-Atlantic 
covers an immense tract known as the Sargasso Sea. 

{b) The species of Fucus and Sargassum are washed ashore in great 
quantities during violent storms, constituting the bulk of the 
' wrack " of the coasts. They furnish valuable manure for enrich- 
ing the soil, and are largely used for this purpose. From their ashes 
alkalies and iodine are obtained. 

{c) In the Silurian period Fucoides antiquus represented the order 
Fucaceae. In the Devonian period the order was abundantly repre- 
sented. Fucus, Sargassum, and other genera were already in exist- 
ence during Tertiary times. 






FUCACE^. 2^9 

Abrangement of the Classes and Orders of the Oophyta. 



I 

i 

Zoospores? 



o 
o 



^ e 





ID 


8 


ii 




•c 


n^ 


cu 


fl 


-f^ 


t>0 


■-I 




eS 


o 


> 



m 



(Edogonie^. V Cceloblaste^. Fucace^, 



CHAPTER XVII. 

CARPOPHYTA. 

356. — The distinguishing characteristic of the plants 
y/hich constitute this vast division is the formation of a 
sporocarp, as a result of the fertilization of the female organ. 
The sporocarp consists, except in the simplest cases, of two 
parts essentially different from each other, viz., (1) a fer- 
tile part, which either directly or indirectly produces spores^ 
sometimes a few, or even one, or, on the other hand, a very 
great number ; (2) a sterile part, consisting of cells or tis- 
sues developed from the cells adjacent to the fertile part, 
and so formed as to envelop it. This group includes plants 
with chlorophyll, and a large number of species which are 
parasitic or saprophytic, and which, as a consequence, are 
destitute of chlorophyll. In the former, the sporocarp is 
small in proportion to the size of the vegetative parts of the 
plant ; but in the latter, where the vegetative parts are great- 
ly reduced, the sporocarp is proportionately large. In this 
the parasites and saprophytes of the Oarpophyta are like 
those of the Phanerogams, in which the vegetative or assimi- 
lative organs are smaller than in those which contain chlo- 
rophyll ; thus the very large sporocarp of many of the Asco- 
mycetes and the Basidiomycetes, and their relatively small 
mycelium, maybe compared to the large reproductive organs 
and the reduced stems and leaves of the Bafffesiacece.'^ 

* This comparison must not be misunderstood. It does not imply 
homology of the parts compared, but it is intended to compare the 
vegetative and reproductive organs of the one group of plants, func- 
tionally considered, with those of the other. There can be no doubt 
that functionally the giant flower of liafflesia is the equivalent of the 
sporocarp of a Peziza, while structurally they are not equivalent ; in 
other words, they are analogues, but not homologues. 



GOLEOGHJETE. 271 

357. — The female organ is in this division called a car- 
pogonium, which consists of a single cell {e.g., Coleochcete, 
some Ascomycetes, and the Gharacece), or of several cells {e.g., 
FloridecB and most Ascomycetes). In some cases a projec- 
tion, called the tricliogyne, is attached to the carpogonium ; 
its function appears to be the conveyance to the carpogonium 
of the fertilizing influence received from the antheridium. 

358. — The antheridium is here, as elsewhere throughout 
the Cryptogams, much more variable in structure than the 
female organ. In some cases it is applied to the carpogo- 
nium in fertilization, while in others it produces spermato- 
zoids ; in either case contact with the carpogonium is either 
direct {Podosphcera, Cliaracece), or indirect, through a tri- 
chogyne {e.g., Coleochmte, Floridem, Peziza). 

359. — The plant-body shows in general a more joerfect 
development in the Carpophyta than in the j)receding di- 
visions. While it is but little developed in the parasitic and 
saprophytic species, it is well developed in many of the Flu- 
ridem and the Cliaracece. In these classes there is often a 
considerable amount of differentiation of the plant-body 
into caulome and phyllome. 

§ I. OOLEOCHJETB. 

360. — The genus Coleochmte maybe taken to represent the 
simplest form of sexual reproduction in this division. The 
species are all small green fresh-water plants, composed of 
dichotomously branching filaments, which are arranged ra- 
dially upon a central disc (or sometimes arranged upon irreg- 
ularly branched threads) ; the diameter of each cushion- 
like mass is from 1 to 2 mm. (.04 to .08 in.). 

361. — Eeproduction takes place both sexually and asexu- 
al ly. The latter is by means of zoospores which arise in the 
vegetative cells, by the protoplasmic contents becoming, in 
each case, converted into a single spherical bi-ciliated zoo- 
spore, which escapes through a round hole in the cell-wall 
{D, Fig. 183). 

362. — The sexual organs and process bear some resem- 
blance to those of (Edogoniaceae. The female organ, the 



2rz 



BOTANY. 



carpogonium, is a single cell, wide below, and tapering above 
into a long slender canal, the tricliogyne, which is open at 
its apex {A, og, Fig. 183). The carpogonium is the terminal 
cell of a branch, which in its development swells up, while 
at the same time elongating into a tube. In the swollen basal 
portion there is a considerable mass of protoplasm, which is 
the essential part to be fertilized. 

The male organs, the antheridia, are formed as flask-shaped 
protuberances which grow out of adjoining cells ; they be- 




Fig. l^^.— Coleochcete pulvinata. A, portion of fertile plant ; an, antheridia; og, 
carpogonia— each with a trichogyne ; z, z, spermatozoids ; A, hairs, with sheathing 
bases. y>', fertilized carpogoniiim stirrounded by covering, r ("pericarp"), the whole 
constituting the sporocarp. C, sporocarps burst open, showiag the interior tissue, 
sell ; r. conical cover (" pericarp"). D, zoospore? (swarm-spores) I'rom C. X 350. — 
After Pringsheim. 

come cut off from the cells from which they grow, by trans- 
verse partitions. In each antheridium a single oval bi- 
ciliate spermatozoid is formed {A, z, z, Fig. 183). 

363. — Fertilization is doubtless effected by these sperma- 
tozoids coming in contact with the protoplasm of the carpo- 
gonium, but the actual entrance of the former has not yet 
been seen. After fertilization the protoplasmic mass in the 
carpogonium increases considerably in size, and becomes 
surrounded by a cellulose coat of its own. The cells which 



FLOBIDE^TJ. 273 

support the carpogonium send out lateral branches, which 
grow up and closely invest it, and by their growth finally 
cover it entirely (excepting the trichogyne) with a cellular 
^* pericarp" {B, r, Fig. 183). The whole mass, including 
the fertilized carpogonium and its investing "pericarp," 
constitutes the simplest form of s2Jorocarp. 

364. — The germination of the sporocarp takes place (the 
next spring) by the swelling of the protoplasmic contents, 
and the consequent rupture of the "pericarp;" the inner 
portion becomes changed into a many-celled mass ( 6', Fig. 
183), which gives rise to bi-ciliate zoospores closely resembling 
those developed from the vegetative cells. From each zoo- 
spore a new plant eventually arises. 

{a) These little plants occur in fresli- water pools as little green 
masses adhering to leaves, sticks, etc. According to Wolle, we have 
five species. 

(&) The sexual process and the development of the sexual organs oc- 
cur in May, June, and July. 

(c) Nothing can be attempted in this place to determine the grouping 
of Goleoch(Ete with other Carpophyta. Its evident relationship to the 
Perisporiacese in the Ascomycetes suggests that possibly the latter 
class may have to be broken up, and the first two orders united with 
Goleoch(Ete to form a new class. Certainly the relationship between 
Coleochmte, Perisporiacese, and Tuberaceae is much closer than between 
the two last named and the other orders of Ascomycetes. There 
can be but little doubt that the Ascomycetes are held together by char- 
acters which are now of but secondary value, drawn as they are from 
the asexual fruiting, while characters which are of far greater value, 
derived from the sexual organs, are disregarded. 

§ II. Class Floride^. 

365. — In the Floridese the reproduction is generally 
asexual as well as sexual. The former is by means of cells 
which originate from a division of a mother-cell into four 
parts ; on account of their number they have received the 
name of tetraspores {A, B, t, t, Fig. 184). These appear 
to replace the swarm-spores of other algge, and may also be 
compared to the conidia of certain fungi ; they are destitute 
of cilia, and are, as a consequence, not locomotive. They 
develop from the terminal cells of lateral branches, or from 
the cells of ordinary thick tissues, sometimes deeply imbedded. 



274 



BOTANY. 



366. — The sexual organs consist, as in Coleoclmte, of 
carpogoiiia and antheridia. The latter are composed of one 
or more mother-cells, situated singly or in groups on the 
ends of branches {A and B, a, a, Fig. 185). The sperma- 
tozoids are small, round bodies, which are destitute of cilia, 
and, as a consequence, incapable of independent movement 
(A, X, Fig. 185) ; they are carried about by currents of 

water, and in this way brought to 
the carpogonia. 

367. — The carpogonia are some- 
what variable as to their complex- 
ity, being much more simple in 
the lower orders than in the high- 
er. In the genus Nemalion the car- 
pogonium consists of a single cell 
{B, h, Fig. 185), resembling Coleo- 
climte closely in this respect. It 
is thickened below, and elongated 
above into the trichogyne, which 
differs from that in Coleoclimte in 
^^-•.^^"^i"-r'^?\-''?P'''"^5-?^ ^^°"^' not beins' open at the top. When 

ese. A,oi Lejohsiamedtterranea ; & J i 

t, tetraspores.-After Sachs ^, of the spermatozoids are set free from 

Corallina officinalis ; t, tetraspores ^ i i i ii 

in a cup-shaped extremity of a the antheridia thcy attacn tnem- 
branc .— er er e ey. sclves to the tricliogyne, as shown 

in Fig. 185 ; the result of this contact of the spermatozoids 
with the trichogyne is the fertilization of the carpogonium, 
which immediately enlarges, and at the same time undergoes 
division into many cells, which grow into short, crowded 
branches, bearing a spore at the end of each (D and ^, 
Fig. 185). To this growth, which includes the spores and 
the short branches which bear them, and which resulted from 
the fertilization of the carpogonium, the name of sporocarp is 
applied. In the genus under consideration the sporocarp is 
a comparatively simple growth, as compared with the degree 
of complexity it reaches in some other orders of this class. 

368. — In the genus LejoUsia, the carpogonium, before 
fertilization, consists of several cells {A, h, Fig. 185),; the 
trichogyne is in connection with certain of the exterior cells 
of the carpogonium, but not directly with its central cell. 




FLORIDE^. 



275 



Upon fertilization taking place, wliich is as in Nemalion, 
the peripheral cells of the carpogonium (excepting those con- 
stituting the tricliopJiore — i.e., the trichogyne-bearer) undergo 
division, and become developed into articulated branches, 
which lie side by side, and form a more or less spherical 





Fig. \9i^.—A,Lejolisia mediterranea. r, root-like processes (rhizoids) ; a, antherid- 
ium ; a?, spermatozoids ; b, carpogonium, with trichogyne, to the apex of which two 
spermat( zoids ar.^ attached; 5, section of ripe sporocarp ; t, ripe spore escaping. B, 
Nemalion muUifidum. a, branch with antlaeridia and spermatozoids ; &, carpogo- 
nium, with trichogyne, the latter with spermatozoids attached to its apex. D and E, 
development of the sporocarp of Nemalion. x 150.— After Bornet. 

organ, the so-called "pericarp." In the meantime the cen- 
tral cell of the carpogonium develops processes or outgrowths 
which eventually become spores, occupying the cavity of the 
"pericarp" {A, 5, Fig. 185). An interesting fact in this 
connection is that neither the trichogyne nor trichophore 
take part in the development subsequent to fertilization ; in 
other words, the cells which directly receive the influence of 
the spermatozoids do not themselves undergo a subsequent 
development, but adjoining ones do develop, on the one 
hand, into the spores, and on the other into the filaments 
of the pericarp. The sporocarp in this genus is thus seen 
to be somewhat more complex than in Nemalion, including 



276 



BOTANY. 



the pericarp, in addition to the parts found in the latter 
genus. 

369. — In the genus Dudresnmja there is a curious and 
complicated sexual process. After the fertilization of the 
trichogyne, a long '' connecting tube" {d, Fig. 18G) grows out 
from beneath the trichoi^hore, and comes in contact with the 

fertile branches (/, /, 
Fig. 186), to the ter- 
minal cells of which it 
becomes closely applied. 
These fertile branches, 
which grow as lateral 
branches on the same 
plant as the trichogyne, 
are the true female or- 
gans, and fertilization 
is consummated only 
when the connecting 
tube comes in contact 
and coalesces with 
them. The result of 
this curious process is 
the production of a spo- 
rocarp on each fertile 
filament. 

{a) This class is a large 
and interesting one, but un- 
fortunately it cannot be 




Fig. IS&.—Dudresnaya purpnrifera. tr, tricho- 
gyne, with spermatozoids attached; ct, connecting- 
tube which grows out from below the base of the 
trichogyne, and conies in contact with the fertile 
branches,/,/," ct', young connecting-tube,— After 
Thurtt and Bornet. 



studied readily except near the seaside, and even tlien, from tlie 
fact that the species mostly inhabit the deeper waters, it presents many 
difficulties. The plants are mostly red or violet in color, although this 
is not due to the absence of chlorophyll. The red color is due to the 
presence of a pigment {phycoerythrine), which is soluble in cold fresh 
■water ; its solution is carmine-red in transmitted light and reddish yel- 
low in reflected light. Upon extraction of the phycoerythrine the 
plants are Ibund to be green from the presence of the chlorophyll 
which had been masked by the brighter pigment. 

(&) There are many orders in this class, the following of which are 
represented in the United States * 

* The sequence of the orders is that given by Dr. Farlow in his 
** List of the Marine Algae of the United States," 1876, published in the 



FLOBIDE^. 277 

Order Rliodomelem, of wliicli Daaya and PolysipJionia are common 
genera. 

Order Ghylocladiece, represented by only two Californian species. 

Order Sphcerococcoidece, represented abundantly by species Belesseria, 

Order Coralliiiece, containing plants wliicli are remarkable for the 
large amount of calcium carbonate they contain. CoraUinais abundant. 

Order Gelidiece, represented by Gelidium. ' 

Order Hypiiece, including only a few species of one genus Hypnea. 

Order Rhodymeniece, of which Rhodymenia and Lomentaria are com- 
mon genera, Rhodymenia palmata, the " Dulse " of our coasts, is used 
as human food. 

Order Spongiocarp ce, with one species of Polyides. 

Order Squamariece, with one species of Peyssonnelia. 

Order Batracliospermece, to which Nemalion (Fig. 185, B) belongs. 

Order Wrangeliece, with two species of Wrangelia. 

Order QiqartinecB^ of which Ghondrus crispus, the Irish moss so 
largely used for food, for making blanc mange, etc., is the best-known 
of the many species on our coasts. 

Order Cryptonemiece, represented mainly on our Southern and Pacific 
coasts. ScMzynemia edulis, of Europe and our Western coasts, is 
used as human food. 

Order Bunion'iece, to which Halosaccion of our Eastern coast belongs. 

Order Spyridiece, represented by Spyridia of our Eastern coast. 

Order Ceramiece. This order contains algae " which are either strictly 
monosiphonous (i.e., composed of a single tube) and filiform, or which 
are more simple in their structure than others, approaching in this re- 
spect the Confervacese. It abounds in species which display the most 
exquisite combination of ramification and coloring." A lar^e portion 
of our marine flora is composed of individuals of this order, as ^' they 
abound on our coasts in every little rocky pool, onevery piece of wood 
work exposed to the waves, on rocks and stones, and, above all, on the 
stems of the larger or firmer algae, or even on marine Phanerogams, 
which they fringe in the most exquisite way with every shade of red, 
from a bright rose to purple. "f 

Lejolisia {A, Fig. 185) and Budresnaya (Fig. 186) are genera of this 
order. Callithamnion is represented by many species on both our At- 

Re.poH of the JJ. 8. Fish Commissioner for 1875. It is modified from 
Thuret's arrangement. The arrangement of the orders and the group- 
ing of genera into orders are not based upon sexua' characters, and con- 
sequently must be regarded as to a considerable extent artificial. The 
first-named orders in the list are higher than those that follow. 

f " Introduction to Cryptogamic Botany," by M. J. Berkeley, 1857, p. 
178. The student is also referred to Harvey's " Nereis Boreali-Ameri- 
cana," a " Contribution to a History of the Marine Algse of North 
America," publislied by tlie Smithsonian Institution, 1852 to 1858. 



278 BOTANY. 

lantic and Pacific coasts. Ceramium ruhrum is a very common spe 
cies. 

ic) The order Corallinese was represented in the Silurian by a spe- 
cies of Gorallina. Others occur in tlie Secondary (Jurassic) and Ter- 
tiary. Chondrites represented the order Gigartinese from the Permian 
to the Tertiary (Miocene). The order Sphserococcoideae was represented 
in the Secondary by Jurassic species of SphcErococciies, and in the Ter- 
tiary by Delesseria. In the order Rhodomelese a species of Polysi- 
•plionides occurs as a fossil in the Tertiary. 

§ III. Class Ascomycetes. 

370. — -This large class includes chlorophyll-less plant? 
which diifer much in size and appearance, but which agree 
with one another, and differ from all other Carposporeae in 
producing their spores (ascos^jores) in sacs (asci). The sex- 
ual reproductive organs, consisting of carpogonia and anthe- 
ridia, are produced upon the mycelium, and, after fertiliza- 
tion, a sporocarp, which includes the asci and ascospores, is 
developed. The asci are, at first, single cells at the ends of 
branches which result from fertilization of the carpogonium ; 
in these, ascospores arise by internal cell-formation. The 
most common number of ascospores is eight in each ascus, 
but it sometimes exceeds, and frequently falls short, of this 
number, there being often no more than one or two. The 
asci are in many cases arranged side by side in a compact 
mass, forming a spore -bearing surface, the liymenium. In 
addition to the ascospores there are generally one or several 
other kinds of spores, which are developed on the same my- 
celium as the sexual organs, or on another, the latter case 
being one of an alternation of generations. 

371. — The Ascomycetes are readily separated into a num- 
ber of well-marked groups, which may not all turn out to be 
coordinates. For the present they may be treated as orders. 

3 7 2. —Order Perisporiacese (or Erysiphaee83). In this 
order the plants, which are mainly parasitic, are composed 
of branching articulated filaments, which form a white web- 
like film upon the surface of the leaves and stems of their 
hosts. There are both sexual and asexual spores, and of 
the latter there are in most cases two or three different kinds, 
which are produced earlier than those that result from a fer- 



PERISPORIACEJE. 



279 



tilization. The sexual organs and the sporocarp resulting 
from the act of fertilization bear a striking resemblance to 
those of Coleoclicete, the difference being such as may be ac- 
counted for by considering the aquatic habits of the one, and 
the aerial and parasitic or saprophytic habits of the other. 

373. — In the parasitic PerisporiaceceihQ jointed filaments 
of the mycelium closely inyest and cover the leaves and 
other tender parts of their hosts, and draw nourishment 
from them by means of haustoria, which project as irregulaj 
pullulations from the side of ^ 

the hyphse next to the epider- . m 

mis (Fig. 187) ; these haustoria 
apply themselves closely to the 
epidermis cells, and, in some 
cases at least, appear to penetrate 
them.* The crossing and rami- 
fying hyphge soon send up many 
vei'tical branches, in which parti- 
tions form at regular intervals ; 
the cells thus formed are at first 
oblong and cylindrical, with flat- 
tened ends ; but the topmost one 
soon becomes rounded at its ex- 
tremities, and the others follow ^.^^ is^.-w.-yu,^, iom^m) 

in quick succession, thus Pivino- Tuchen. ^, ap-ec^ >f a V6^^4.'.tive 

^ J^ ^ nypha, m, m, ui.on a frafjraent ot the 

rise to a monilliorm row OI loose- epidermis of the leaf of the vine, and 

, , , 1 T IT , • 1 T T to which it is fastened by the Ijaus- 

ly attached elliptical or rounded toria, h; &, an isolated piece of a 

Tji- -j^8\ ^^^^^l^^^ h^pha, with the hansto- 




rium. A, g,(.&u in aide view. X 370. 
After Vori Mohl. 



cells, the coniclia (Z, Fig. 188). 

These fall off and germinate at 

once by pushing out a germinating tdhe, which gives rise 

to a new mycelium. 

374. — The sexual j)rocess, which in most species takes 



* De Bary (" Morpliologie und Physiolo^ie der Pilze,'* etc., 1865, p. 
19) says tliat tlie haustoria of the investi^xated species do not penetrate 
into the epidermis cells ; while Sachs ('• Lehrbuch, 4te Auflage," 1874, 
p. 312) says that haustoria are sent into the epidermis cells. A myce- 
Hum on Poa pratensis (probably of Erysiphe communis) examined in 
Ji.877 appeared to have sent its haustoria through the outer walls of 
the epidermis cella 



280 



BOTANY. 



place late in the season, is as follows : where two filaments 
cross each other or come into close contact they swell 
slightly and send out from each a short branch ; one of these 
thickens and assumes an oval form, becoming at the same 
time separated from the filament by a partition ; this is the 
carpogonium (///, c, Fig. 188, and c, Pig. 189). From the 
swollen part of the other filament a corresponding branch is 
given off, which grows up in contact with the carpogonium ; 
uear its extremity it forms a partition, which thus cuts 




Fig. 188.—/., conidia-bearing hypha of Sphmofheca vaTinom. JJ., the ripe pporo- 
carp of the same ; a, the single ascus escaping from the perithecium. h ; only a few 
of the hypha-like appendages of the perithecinm are shown. III., sexual organs of the 
same: c, carpogonium : p, antheridium. IV., ihe formation of ihe perithecium by 
the tjrowth of the enveloping cells, h : c, carpogonium ; p, antheruiium. F., section 
of the voung sporocarp oi Sphoerotheca Castagnei ; c, carpogonium ; a. the young 
ascus ; h, h, cells of the perithecium. I. and //. after Tulasne ; ///,- V. after De 
Bary. 

off a small rounded terminal cell, the antheridium (IFL, p, 
Fig. 188, and b, Fig. 189). Immediately after the forma- 
tion of the antheridium the effect of fertilization shows itself 
in the growth from below the base of the carpogonium of eight 
or ten branches, which join themselves to its sides and to one 
another, finally completely investing it {IV., Fig. 188, and 6^, 
Fig. 189), Each of these joined enveloping branches be- 
comes transversely divided several times, thus giving to the 
covering layer a distinctly cellular structure. The enclosed 



PERISPORIACE^. 



281 




oarpogonium becomes divided in such a way tliafc from one 
portion of it an inner layer of cells is formed in contact with 
the outer envelope described above. From the remaining 
central part of the carpogonium one ascus (in Sphcerotheca 
and Podosplicera), and in the other genera two or more, are 
developed. In each 
ascus from two to d 

eight ascospores arise 
by internal cell-for- 
mation (//, a, Fig. 
188). The sporocarp 
(technically called 
the perifhecium) be- t^. .„„ ^^ , . „ . ^ „. .^ . 

-^ -^ Fig. 189.- -The sexual process m Erysiphe Ctctvon- 

comes dark and hard, acearum. «, threads of mycelium ; &, antheridium; 

-, „ . c, carpogonium ; rf, young sporocarp ; e, older sporo- 

and irom its outer carp. HigWy magnified.— After CErsted. 

cells there grow out long filaments (technically known as 
appendages), which are usually septate, and of a particular 
shape in each genus ; thus in Podosplimra and Microsplmra 
they are dichotomously branched ; in Plnjllactinia they are 
straight and needle-shaped ; in Unchmla they are curved 
regularly at their tips (Fig. 190), while in the other genera 
they are tortuous, and simple or irregu- 
larly branched. The perithecia remain 
during the winter upon the fallen and 
decaying leaves, and finally, by rupturing, 
permit their asci, with their contained 
ascospores, to escape. 

375. — There are usually present some 
Jl^^^uk^SSl fdun. otlier organs, which bear 8mall spore-like 
ca; the appendages of bodics, bu^ whoEc fancticn is not Certain 

the perithecmm are 

curved in a circinate ly known, Thcsc orsjaus, which are 

manner at their free ex- "^ i 

tremities.— After Cooke, known as pycmdia, are clavate, ova^te, or 
nearly spherical in shape ; the bodies they contain (i,je so- 
called pycnidio-spores) in their cavities are usually oblong 
or elliptical. 

376. — In the genus Eurotium (composed of saprophytes) 
the conidia are produced in a slightly different way. The 
mycelium, which is common on cirticles of food, as bread, 
pastry, preserved fruit, etc., and on poorly dried specimens in 




S82 



BOTANY. 



the herbarium, sends up vertical hy23h8e, which swell up at 
the top, and bear a large number of small protuberances or 
branches, the sterigmata {A, c, 8t, Fig. 191). Each sterigma 
produces gradually a long chain of conidia, so that each 




Fig. VS\.—-Eurotmm repens. A, a portion o* the mycelium, with erect hj'-pha, c, 
bearing at its top a radiating cluster of sterigmata, st, from which the conidia have 
fallen ; as, young carpogonium— below it a younger branch is beginning to coil spi- 
rally to form another carpogonium. B, the carpogonium, as, and the antheridium, j9. 
G, the same beginning to be surrounded by the enveloping branches whch grow out 
jrron: )t8 base. D, sporocarp. E, F, sections of unripe sporocarps ; v), outer wall ; 
j\ iuner cells of sterile tissue ; as, developing cnrpogonium, giving rise to branches 
from which asci are produced. G, an ascus containing eight ascospores. H, ripe as- 
cospore. Highly magnified.— After De Bary. 



yertical hypha is terminated by a round mass, made up of 
ihese radiating strings of conidia. The sexual organs appear 
a little later than the conidia. The end of a branch of the 
mycelium becomes coiled into a hollow spiral {Ay as. Fig. 



PERISPOBTAGE^. 283 

191), which constitutes the carpogonium, and which is soon 
divided by cross-partitions into several cells. From below 
the spiral there pushes out a branch (the antheridium), which 
grows upward, and brings its apex in contact with the upper 
cells of the carpogonium {B, Fig, 191). After this pro- 
cess^ which constitutes fertilization, other branches grow op 
around the carpogonium, and finally completely enclose it 
as in the parasitic genera described above {C, D, E^ and F^ 
Fig. 191). By the subsequent growth and division of the 
enveloping branches, the carpogonium becomes imbedded in 
a thick parenchymatous mass. In the meantime, from the 
cells of the carpogonium branches bud out and penetrate the 
surrounding parenchyma {F, Fig. 191), and finally produce 
eight-spored asci on their extremities ((t. Fig. 191) ; after a 
time the asci are dissolved, and the sporocarp, now of a sul- 
phur-yellow color, contains only loose ascospores, intermingled 
with the debris of the broken-up asci and parenchyma,* 

The plants of tliis order are abundant and easily studied. The 
following partial list will enable the student to intelligently begin his 
investigations : 

Parasitic Plants. 

A. Perithecium containing a single ascus. 

Appendages floccose Genus, Sphmrotheca. 

Appendages dichotomous " Podosplicera. 

B. Perithecium containing many asci. 

Appendages needle-shaped, rigid Genus, Phyllactinia. 

Appendages hooked " Uncinula. 

Appendages dichotomous ** Microsphmra. 

Appendages floccose " Erysi/phe. 

SpliCBrotheca pannosa occurs on wild gooseberries, on whose stems, 
leaves, and fruits it forms brown felted masses. In its conidial stage 
it is frequently so abundant on the leaves of roses as to entirely destroy 
them. 

8. Gastagnei sometimes occurs upon the hop in such abundance as to 
destroy the crop. 

* The student is referred to De Bary's " Morphologie \ind Physiolo. 
gie der Pilze," etc., 1865, p. 162. A translation of the part relating to 
the ErydpJiei appeared in " Grevillea," Vol. I., p. 153. 



'-^84 BOTANY. 

Podosplmra Kunzei may be found on the leaves of the cherry and 
apple, which it injures greatly in some cases ; the conidia may be ob- 
served in midsummer, and the sexual process and formation of perithecia 
in autumn. 

PJiylhtctinia guttata may be obtained in great abundance in autumn 
upon the leaves of the hazel and ironwood. 

Uncinuld. adunca is frequently abundant on willow ieaves in the 
autumn (Fig. IDO). 

U. spiralin is tne species to whose conidial stage the name Oidium 
Tuckeri has hitherto been applied in this country. It occurs on the 
grape, and does great injury. According to Dr. Farlow, it is not cer- 
tain that the so-called Oidium Tuckeri of this country is identical with 
what is so named in Europe, and which is even more injurious to 
grapes in that country than in this. 

U. circinata occurs on the leaves of the red and silver maples in the 
autumn. 

Microsphmra Friesii is one of the most common species. It may be 
found in the conidial stage at any time during the summer on the 
leaves of tlie lilac, and late in summer or in autumn the perithecia are 
usually abundant. 

M. (xtensa is a nearly related species, often very common on oak 
leaves. 

Erysiphe lamprocarpa, which may be found on Comi^ositse (especially 
on Helianthus), and also on wild verbenas, is readily distinguished by 
its two-spored asci. The commonness of this species makes it a valua- 
ble one for study. 

E. tortilis may be frequently obtained on the leaves of the Virgin's 
Bower. 

E. Martii occurs in great abundance upon cultivated peas, greatly 
to their injury. In summer it covers the leaves and fruits with a 
white mould-like growth, which is the conidial stage of the parasite ; 
as autumn approaches the mycelium becomes darker, and finally large 
numbers of perithecia may be found, 

E. communis appears in early summer on grass leaves, where the 
vegetation is rank. In autumn the perithecia may be found in abun- 
dance on Ranunculacese (especially on Anemone) growing in grass. 



Saprophytic Plants. 

Eurotium herbariorum may be readily obtained for study by placing 
a few green specimens of Phanerogams in an ordinary plant-press and 
permitting them to remain until they become mouldy. The conidial 
stage, which first appears, is what has long been described as a distinct 
fungus under the name of Aspergillus glaucus ; somewhat later the 
bright yellow perithecia will be found in abundance. 



TUBER AC E^^. 



285 



377. — Order TuberacesB. In this order the sporocarp is 

a rounded underground mass, composed of pseudo-jDaren- 

chyma and the asci with their contained 

ascospores. In the Truffle (Tuber) the 

sporocarp is large, and dark colored and 

warty, on the exterior. Internally it con- 
tains narrow tortuous chambers, on whose 

walls are the asci, containing two to eight 

usually areolate or echinulate ascospores 

(Fig. 192, A and B). The sexual organs, 

as well as the early stages of the Truffles, 

are unknown. 

378. — The common "blue mould, found 

on all sorts of decaying bodies, and known 

as PenicilUum glaucum (or P. cnista- 

ceum), has recently been found by Brefeld 

to be a member of this order. Its life-his- 
tory is now i^retty well known, and it in- 
dicates what the early 
stage of the Truffle 
must in all probability 
turn out to be. In 
PenicilUum the my- 
celium sends up a large 
number of vertical 
hyphag, which branch 
at the top, and produce chains of conidia 
(Fig. 193). It aj)pears, from Brefeld's 
researches, that this stage is the only 
one which the plant passes through 
under ordinary circumstances ; by care- 
ful culture, however, he succeeded in 
making it pass into its sexual stage. 
He found the sexual organs to be in all 
essentials similar to those of Eurotium 
(Fig. 191) ; like it, the carpogonium is a spirally twisted end 
of a hypha, and the antheridium a branch growing out from 
below it. The subsequent development is also much as in 
Eurotium ; a thick covering forms over the fertilized carp- 





Fig. n2.— Tuber me- 
lanosporum. A, a por- 
tion of a transverse sec- 
tion, showing the asci, 
with contained asco- 
spores ; i?, an ascus 
with ripe ascospores. 
Both much magnified. — 
After Tulasne. 



^ 



Fig. 193. — PenicilUum 
ehartarwni, showing co- 
nidia-bearing hypha ; at 
the side is shown an iso- 
lated chain of conidia. 
Magnified.— After Coolie. 



286 



BOTANY. 



ogonium by the growth of many basal enveloping brandies, 
and inside of this the carpogonium increases in size, and 
sends out branches, which finally produce eight-spored asci. 
The little tuber-like mass thus formed is yellowish, and of 
the size and appearance of a coarse sand grain. 

{a) Aside from Penicillium, we have in this country very few repre- 
sentatives of this order. Two or three species of Tuber have been 

recorded, and two of Elaphomy- 
ces* 

(b) In Europe, where they grow 
abundantly, Tuber cestivum, T. 
melanosporum, and T. magriatum 
are gathered for food. They are 
found by the aid of dogs and pigs, 
which are trained to search for 
them. 

379. — Order Helvellacese 

(or Discomycetes). These 
are for the most part disc-like 
or cup - like saprophytes, 
which frequently attain large 
dimensions. The hymenium 
is spread over the upper and 
generally exposed surface of 
the full-grown plant, which 
is in reality tho sporocarp. 
In Peziza, one of the prin- 
Fig. 194.— Sexual orfans of Pm«a co«- cipal genera, the sexual or- 

fluem, highly magnified. A, at time of p'anS OCCUr OU the mVCelium 

fertilization; a, carpogonium ; /, tricho- fe"'^-^" ^^^ J 

gyne ; «', antheridium. B, after fertiliza- on Or in the OTOUnd ; the 

tion ; A, /i, the hyphae from which the re- , • i i n 

ceptacle is developed.— After Tulasne. euds 01 Certain hyphSB SWCli 

up into ovoid vesicles, the carpogonia (Figs. 194 and 195), 
each of which is provided with a more or less bent and 
curved appendage, the tricliogijne (Fig. 195, and /, /, Fig. 
194). From below the carpogonium a branch grows out, 
and, curving around, becomes closely applied by its tip to 
the extremity of the trichogyne (Figs. 194 and 195). The 




* See Bulletin of the Torrey Botanical Club, November, 1878, for the 
species of Tuber discovered in North America. 



HEL YELLACE^. 



287 



immediate result of this j)rocess of fertilization is the 
ding out and upward growth of a large number of hyphge 
beneath the carpogonium 
{B, Fig. 194) ; these form 
a dense felted mass, from 
which, eyentually, there 
rise yertical, closely 
crowded hyphae, which 
form the hymenium i^A, 
Ji, Eig. 196). In the ter- 
minal portions of certain 
of the yertical hyphae 
the protoplasm condenses 
around certain points, and 
thus gives rise to asco- 
spores {B, a to /, Fig. 
196). In this genus (Pe- 
ziza), as well as most 
others of this order, the 
ascospores are always eight 
in each ascus. At matur- 



bud- 
from 





Fig. 195. 



Fig. 196. 



Fig. 195.— Sexual organs of Peziza omphalodes. The two spherical carpogonia have 
each a crooked trichogyne, and to each trichogyne is applied the swollen end of the 
curved antheridium. Much magnified.— Afier Tula?ne. 

Fig. VdQ.—Pesiza convexula. A, vertical section of the whole plant ; h, hymen- 
ium ; s, sterile tissue forming a margin, j;, and giving oflf below fine hyphse which 
pass into the soil, x 20. i?, vertical secticm of a portion of the hynienliim ; atof, 
asci, with ascospores in various etages of development, intermixi-d with slender 
paraphyses ; sh, sub-hymenial hyphae. x 550.— After Sachs. 

ity the ascospores escape by the rupture of the walls of the 
asci, this generally taking place at the upper or free end. 



28S 



BOTANY. 



380. — In Ascohohis the carpogonium consists of a row of 
cells ; it develo2:)s from the end of a branch of the mycelium, 
which becomes curved and divided by several partitions (c, 
Fig. 197). On account of its peculiar shape it is frequently 
spoken of as the ^' vermiform body," or scolecite. From 
another portion of the mycelium an elongated and branched 
antheridium rises, and comes in contact with the free end of 
the carpogonium {I, Fig. ^r 

197) ; after this pro- 
cess numerous filanK'nts 
branch from the mid- 
dle cell of the carpogo- 
nium and pass upward, 
eventually producing 
asci {s and a, Fig. 197). 
At the same time an 
abundant growth of hy- 
phae takes place from the 
mycelium below the car- 
pogonium, and from this 
the greater part of the 
mass of the fruiting 
plant is produced ; it 
also invests the hyme- 
nium, forming the so- 
called i^ericarp which 
encloses it (r. Fig. 197). 
Yerticai branches of the sterile tissue also pass into the 
hymenial layer and constitute the paraphyses. 

381. — The asexual reproductive bodies are but little 
known, but enough is known to indicate that there is at 
least a conidi.'i-bearing stage for these Ascomycetes, as for all 
others. De Bary has shown that the early stage of the little 
plant known as Peziza FucJcelimia is mould-like in appear- 
ance, in fact having been described as a mould under the 
name of Polyactis cinerea. In this stage it grows upon dead 
grape leaves, sending its mycelium through the dead tissues. 
Its vertical hyph^ produce clusters of oval conidia, which 
are much like those produced in the correspondin 




Fig. 197.— Diagrammatic vertical section of 
the sporocarp of Ascoholus furfur aceus. m, m, 
mj^celiuni; c, carpogonium; I, antheridium; s, 
branches bearing the asci, a, a ; p, p, pseudo- 
parenchymatous sterile tissue; r, r, cortical 
portion of sterile tissue— above it fonns the so- 
called pericarp, which surrounds and encloses 
the hymenium, h.—Aitex Janczewsky. 



o- stao^e of 



PYRENOMYCETES. 289 

Eurotium and Penicilluim. In anotlier species, Peziza 
fusarioides, the conidial stage has been pretty certainly de- 
termined to be the growth which was formerly supposed to 
be a species of Dacrymyces ; it consists of little tubercles 
which contain slender linear bodies on branched threads. 
Bulgaria sarcoides is known to bear conidia in an earlier 
stage, which was formerly referred to the genus Tremella 
(Hymenomycetes) . * 

{a) The principal genus of this order is Peziza, which contains many 
species ; they are common on the ground in forests. Ascobolus furfu- 
raceus is common on cow dung. Morchella esciilenta, the Morel, grows 
on the ground in forests. It attains a height of from 10 to 15 centim- 
etres (4 to 6 inches), and bears its hymenium in shallow depressions 
of its convex surface. 

(&) The Morel is edible, and is much used for food in some places. 
According to Dr. M. A. Curtis, some species of Helve'lla, also, are edible. 

(c) Peziza syhatica, P. Candida, and Cenangium Piri occur as fossils 
in the Tertiary. 

382.— Order Pyrenomyeetes. The plants of this order 
are parasitic or saprophytic in habit ; their tissues are usually 
hard and somewhat coriaceous, differing in this respect from 
the Helvellacem, which are generally fleshy ; they differ also 
from the plants of the last-named order in having the hyme- 
nium imbedded in deep cavities {pei^ithecia) with narrow 
openings. In other respects the Pyrenomyeetes present a 
close similarity to the Helvellacece, to which they are doubt- 
less closely related. 

383. — Their general structure may be illustrated by a 
couple of examples. In Claviceps lourjju'^'ea, the fungus 
which produces ergot on rye and other grasses, the first 
stage consists of a profuse growth of the mycelium in the 
tissues and upon the surface of the young ovary (s, A, and 
B, Fig. 198). In this stage, which is called the Sphacelia 
stage, it produces a multitude of conidia on the 'ends of 
hyphge which grow out at right angles to the surface of the 
mycelial mass ((7, Fig. 198, h and i^) ; these conidia fall off 
very easily, and quickly germinate {D, Fig. 198), giving 
rise under favorable cnxumstances to new sphacelia, Avhich 
in turn may produce conidia, and these, new sphacelia, and 

* See further, De Bary, op. cit. , p, 200. 



290 



BOTANY, 



so on. The contucfc of an infected head of rye with an nnin- 
fectcd one is siillicient to communicate the fungus to the 
latter, and doubtless the conidia are also freely carried by the 
winds, and, to a certain extent, by insects. It appears that, 

in some cases at least, 
the germinating co- 
nidia produce, first, 
short hyphae, which 
bear a few small 
spores (s2)o?H(Ua, D, 
Fig. 198, x), which 
themselves g e r m i - 
nate, and "then pro- 
duce the sphaceha ; it 
is doubtful, however, 
whether this always 
takes place. 

384. — After the 
conidial stage, the 
mycelium at the base 
of the ovary becomes 
greatly increased, and 
assumes a hard and 
compact form ; it 
grows with a consider- 
able rapidity, and car- 
ries up on its summit 
the old sphacelia and 
the remains of the 
now-destroyed ovary 
(.4 and B^Y\g. 198)"^. 
The compact, horn- 
shaped, and dark-col- 
ored body which re- 
sults is called the sderotium ; that which is produced upon 
rye is from one to three centimetres long (.4 to 1.2 in.) and 
from two to six millimetres in diameter (.08 to .25 in.) ; on 
other grasses it is usually of less size. The sclerotium occu- 
pies the position of the displaced ovary, and in the autumn 




IK? 



^# 



&-o-ooOo^' 






Fig. 198. — Claviceps purpurea. A, young sclero- 
tium, c, with old sphacelia, s ; p, the apex of the dead 
ovary of rye. B, upper part of A, in longitudinal sec- 
tion, showing sp'iacelia, s. C. transverse section 
through the sphacelia more highly magnified ; m, the 
mycelium, surrounded with the hyphai 6, hearino; co- 
nidia ; p, couidia fallen off ; to, the wall of the ovary. 
2), germinating conidia, forming sporidia. x. A aiid 
B moderately" C and I) highly magnified.— After 
Sachs. 



P TMENOMYCETES. 



291 



falls to the grourd, where it usually remains till the follow- 
ing spring, when its hyphse begin a new growth. As a re- 
sult of this new growth several little branches shoot up, and 
each forms a globular head (the receptacle) at its summit 
{A, Fig. 199). Laig-e numbers of flask-shaped perithecia 
form in the cortical region of the receptacles {B, Fig. 199, cj)); 
each contains many elongated asci, which rise from the bot- 




Fig. l^'d.—Claviceps purpurea. A, a sclerotium (ergot), e, forming the receptacles 
(sporocarps ?), cl. B, longitudinal section of a receptacle, showing the perithecia, cp. 
C, a perithecium, with tlie snrronnding tissue ; cp, its orifice ; hy, hjq^hae of the re- 
ceptacle ; sh, outer layer of the receptacle. D, a single ascus, ruptured, permitting 
the elongated narrow ascospores, sj), to escape. A and B moderately, O and B high- 
ly magnified.— After Tulasne. 

tom of the cayity {O, Fig. 199), and themselves contain 
several greatly attenuated ascospores (D, Fig. 199, sp). 
The ascospores germinate under proper conditions, and pro- 
duce sphacelia, thus completing the round of life. 

385. — Thus far no sexual organs have been found, but 
from the general similarity of these fungi to the Pezizm and 
other Helvellacese, it may be surmised that se^'ual organs and 



292 BOTANY. 

a sexual process precede the formation of eacli receptacle 
which si)riiigs from the sclerotium. It may be, however, 
that eacii perithecium is the result of a sexual act ; in the 
latter case the single perithecium would be the homologue of 
the Peziza cup, while in the former the whole receptacle of 
Claviceps would be homologous to the receptacle of Peziza. 

386. — As a second illustration of the plants of this order, 
the Black Knot (Splicer ia moriosa) which attacks the plum 
and cherry may be taken.* In the spring the hyphae, which 
the previous year penetrated the young bark, multiply 
greatly, and finally break through the bark, and "form a 
dense pseudo-parenchymatous tissue." The knot-like mass 
grows rapidly, and when full sized is usually from two or 
three to ten or fifteen centimetres long ( 8 or 1.2 to 4. or 6. 
in.), and from one to three centimetres in thickness (.4 to 
1.2 in.) ; it is solid and but slightly yielding, and is composed 
of hyphae intermingled with an abnormal development of the 
phloem parenchyma of the host plant ; bast fibres and modi- 
fied vessels of the wood also occur. Externally the knot is 
at this stage of a "very dark brownish -green color," and has 
a velvety appearance, which is due to the fact that its surface 
is covered with myriads of short, jointed, vertical hyphse, 
each of which bears one, two, or more ovate pointed conidia 
(Fig. 200, 1 ) . The conidia fall off readily, and doubtless are 
important agents in multiplying the number of these para- 
sitic growths ; they are produced until the latter part of 
summer, when the hypha branches which bear them shrivel 
up and disappear. 

387. — During the latter part of summer perithecia are 
produced ; but the asci require the greater part of winter to 
come to perfection. In February the ascos23ores are fully 
ripe. The perithecia at this time are nearly globular in 
shape, and are situated in minute papillas (3, Fig. 200) ; the 
asci loosely cover the walls of the perithecia! cavity, and are 
intermingled with slender paraphyses (4, Fig. 200). Each 

* What follows is condensed from a paper on " The Black Knot," by 
Professor W. G. Farlow, in the Bulletin of the Bussey Institution, Vol. 
I., p. 440 (1876). Three excellent plates accompany the paper. 



P TBENOMYCETES. 



293 



ascus contains eiglit ovate ascospores, wliicli are two-parted, 
as is the case in many other members of this order (5, 
Fig. 200). The ascospores escape through a pore in the top 
of the ascus, and in from three to five days begin to ger- 
minate by sending out a tube or small hypha ; sometimes 
two or more hyphse start out from a single ascospore (6, 
Fig. 200). 

388. — Besides the perithecia, there are other cavities 
found which much resemble them, but which contain other 
sui^posed reproductive bodies. In one kind are found the 
stylospores, Avhich are quadrilocular oval bodies, borne on 
long stalks (2, Fig. 200) ; they occur generally in definite 




Fig. 200.— Eeprodnctive organs of Sphoeria mnrbosa. 1, conidia-bearing hyphse 
from a section of the knot on the cherry, made in May ; 2, styloespores ; 3, outline of 
a vertical section of a perithecium, made in winter; 4,twoasci with the contained 
ascospores, enlarged from 3 ; p, paraphyses ; 5, a ripe ascospore ; 6, two ascospores 
in process of germination. All much magnified. —After Farlow. 

joatches on the walls of the globular cavities above men- 
tioned. Their function is unknown ; but in all probability 
they are asexual reproductive bodies. In other perithecium- 
like cavities slender filaments are produced ; these are thesper- 
matia, and the cavities in which they occur are the sperma- 
gonia. Still other cavities, much like the preceding, " are 
lined with short delicate filaments, which end in a minute 
oval hyaline body ; " these small bodies are produced in 
immense numbers; when they are discharged from the cavi- 
ties in which they grow, they ooze out in long jelly-like 
masses. The cavities are called pycnidia, and the small 



294 BOTANY. 

bodies pjciiidio-spores. Neither tlie spermatia nor tlie 
pycnidio-spores have been known to germinate ; but from 
tlie resembUmce of the former to tliose of Cucurhitaria, 
Vcdsa, and otlier genera of this order, which have been seen 
to germinate,* it is quite certain that they, at least, are 
reproductive, and that ^^they are tlie agents for the dissem- 
ination of the species to a great distance," for which they are 
fitted by their extreme minuteness. In all probability the 
pycnidio-spores have also a similar function. 

389. — No sexual organs have as yet been observed. 
Doubtless they exist in the dense tissues of the knot, and 
fertilization j^robably occurs in the spring or early summer, 
while the conidia are being produced on the surface of tJic 
3^oung knot. 

390. — The hyjohae of each year's knot generally penetrate 
downward some centimetres into the uninjured bark, and 
remain dormant there until the following spring, when they 
begin the growth which results in tlie production of a knot, 
as described in paragraph 386. 

(a) The P3'renomycetes include a large number of exceedingly in- 
jurious fungi ; they often attack and destroy not only plants, but also 
insects, upon wliicli their ravages are in many cases very great. 

(&) The classification is as yet in great con fusion. f The principal 
g'enus is Sphcena, which contains many species. Yalsa, Diati-ype , and 
Hypoxylon are other important genera. 

(c) Good specimens of Glamceps purpurea may be obtained from 
almost any rye-field, and more certainly from the isolated bunches of 
rye growing here and there in many fields. By making repeated ex- 
aminations soon after the flowering of the rye the conidia may be 
obtained ; and by gathering the sclerotla and burying them in moist 
sand under a bell-jar, the receptacles may be grown. 

{d) Specimens of Sphceria morbosa for study should be gathered at 
different times in the season — from early spring to the latter part of 
the winter following. The first gathered will be necessary to the 

* Dr. Max Cornu, in " Annales des Sciences Naturelles," Sixtli Series, 
Vol. III., gives the details of his experiments upon germinating the 
spermatia of many Pyrenomycetes. A translation appeared in " Gre- 
villea," 1877 and 1878, Nos. 36 to 39. 

f The student may profitably consult, in studying this diflicult order, 
the finely prepared sets of " North American Fungi," by J. B. Ellis, 
begun in 1878, and still continuing. 



LIGHENES. 



295 



study of tlie youno: and forming knot, wliile the succeeding ones will 
sliow first the conidia, and then the forming perithecia and developing 
asci and ascospores. The last gathered specimens in February will 
show the fully formed ascospores. 

{e) Ergot, which occurs ou rye and many of the forage grasses, is 
poisonous, producing gangrenous sores when eaten in considerable 
quantities. It is used somewhat in medicine. 

(/) Xy^omites in the Jurassic, and Splmria, Phacidium, Bhytisma 
and other genera, in the 

~^^^y^Q^^ 



Eocene and Miocene, are 
the fossil representatives 
of this order. 

391.— Order Lich- 

enes. Lichens agree, 
in all the essentials of 
their structure, Avitli 
the two preceding or- 
ders, HelveUacecB and 
Pyrenoinycetes, and 
there can no longer 
be shown any good 
reasons for not class- 
ing them with the 
latter, under the As- 
comycetes. 

392. — The tissues 
of lichens consist of 
various 
of colorless 
hyphae ; in 



aggregations 
jointed 




Fig. 201.— Transverse section of the thallus of 

, Sticta fuliginosa. o, cortical layer of the upper siir- 

general face ; ?/. cortical layer of lower surface ; 1\ rhizoids 

.,,-,.,, or attaching fibres ; m, medullary layer, composed of 

the hypnse m tne cor- distinct hyphie, many of which are cat transversely ; 

, • 1 " I- -P +1 j7, layer or green goiiidia. Each gonidia group is sur- 

tlCai portion OI tne rounded by a gelatinous envelope. X 550.— After 

thallus are compact- ^^^^^■ 

ed and developed into a pseudo-parenchyma (o and u, Fig. 201, 
and cc, B, Fig. 202), while in the medullary portion they are 
distinct (w. Fig. 201, and cm, B, Fig. 202). In all lichens 
there occur numerous green, blue-green, or brown-green cells, 
the gonidia, which are either scattered through the interior 
(homoomerous), or disposed in one or more distinct layers 
(Jieteromerous) ; of the former, Collema and Leptogium are 



I 



296 



BOTANY. 



examples, while of the latter Usnea, PJiyscia (Fig. 202) 
and Sticta (Fig. 201) may be taken as illustrations. 




if: 



















Fig. 202.— Physcia stellaris. A, a portion of a thallus with two apothecia, ap, 
and several spermaeonia. .<?, s. B, transverse section of thallus through an apothe- 
cium ; cc, cortical layer of pseudo-parenchyma ; g, (/\ gonidial layers ; cm, medul- 
lary layer; fi.h. bypothecium ; t.f^t.t. the hymenium ; th, asci (lliecse'), with 
ascospores. C, scctiou through three spermagouia, s.s,s; rh, rh, rhizoids. Z>, 
eterigmata from the interior of a spermagonium, bearing spermatia, s', s'.— After 
Tulasne. 



LICHENE8. 



29^ 



393. — In tlieir modes of reproduction, also, lichens agree 
with the before-mentioned orders of the Ascomycetes. Like 
them, they produce asci, containing ascospores, spermago- 
nia, with their contained spermatia, and one or more otheT 
organs whose functions are supposed to be reproductive. 

394. — The asci are always developed from the hyphae, and 
have no connection whatever with the gonidia. They arise 
in most (but not all) cases from the hyphae of the interior of 
the lichen. It appears that the particular hyphae which 
produce asci differ from those which are found elsewhere in 
the lichen in being of greater diameter and richer in proto- 




Fig. 203.— Vertical section through the young apothecium of Lecanora subfusca 
(partly diagrammatic) ; ?t, h, hymeniura, composed of (1) paraphyses, which de- 
Teloped from the ordinary hyphae, and (2) the young asci in various stages of de- 
velopment ; sh, ascophorous hyphae, from which the asci develop; e, excipulum— i.e., 
the layer of hyphae upon which, or above which the ascophorous hyphss are borne ; 
y, r, cortical layer of thallus ; m, medullary portion of thallus ; ^, the gonidia. X 190. 
— After De Bary. 



plasm. The asci are developed from vertical, club-shaped 
branches, which penetrate between narrow, vertical branches 
(paraphyses) of the ordinary hyphae (Fig. 203). In many 
cases they are collected in a disc-like surface, forming an ex- 
posed hymenium (gymnocarpous lichens), while in other cases 
they are m the interior of cavities (perithecia), whose walls 
they line (angiocarpous lichens). The ascigerous fructifica- 
tion is in either case technically called an apothecium. 

395. — The spores arise in the asci exactly as in the case of 
Peziza and other Ascomycetes previously described ; that is, 
they are formed simultaneously by the condensation of the 
protoplasm about certain points in tne interior of the young 



298 



BOTANY. 



a^cus (tlie so-called free cell formation). Usually there is a 
considerable quantity of the unused protoplasm left oyer 
after the jiscosDores are fully formed (Fig. 204, a, h, c). The 
usual number of ascospores is eight (Figs. 202, 203, 204), 
although in exceptional genera they range from one or two 
( Umbilicaria) to a hundred or more {Bactrospora, and other 
genera). They are frequently septate, sometimes being di- 
vided into two portions — e.g., PUyscia (Fig. 202) — or 
many, as in Gollema Urceolaria, etc. In the gymnocarpous 
lichens the ascospores escape directly into the air. and this 
they generally accomplish with such force as to be projected 
/ ^ some millimetres ; in the angio- 
^ carpous genera they first escape 
into the cavity of the perithe- 
_ cium, from which they pass out 
O through an opening in its apex. 
^^ 396. — In germination the as- 
cospore commonly sends out a 
germinating tube, which is a 
growth from the endospore ; it 
develops directly into a hj^^ha, 
and becomes branched and sep- 
tate. Bi- or multilocular asco- 

Fig. 204.— Asci and ascospores of nix 

spimrophorus giobiferus, a, young spores usually scud out a germi- 
nating tube from each cell. In 
the genera with very large asco- 
spores — e.g., Megalospora, Per- 
tusaria, etc. — the germination takes place in a Avay somewhat 
different from that just described. In the endospore a 
great number of cavities or canals form {g, Fig. 205), from 
each of which there grows out a germinating tube {d, Fig. 
205) ; these many tubes elongate into hypha?, and become 
septate and branched (/, Fig. 205). 

397. — In addition to the apothecia, with their contained 
ascospores, there are other organs which contain bodies 
which are probably reproductive in their nature. The 
best known of these are the spermagonia (Fig. 202, A, s, 
and Fig. 206), which are small cavities, usually found upon 
the same thallus as the apothecia ; they contain branched 




asci in various stages ; b, the oldest 
ascusin a, more magnified ; c, an as- 
cus nearly ri'pe ; d and/, ripe asco- 
spores. X 390, except b, X 700.— After 
De Bary. 



LICHENE8. 



299 



threads {sterigmata), which line the inside of the wall (Fig. 
202, D) ; npon the sterigmata are borne large numbers of 
minute cells (the spermatia) , which fall off and are per- 
mitted to escape through the small opening at the apex of 
the spermagonium. It is unknown whether these germinate 
or not ; some botanists have supposed them to be sexual in 
their nature — hence their name, spermatia ; the recent in- 
vestigations of Stahl, to be referred to below, seem to indi- 




Fig. 205.— Germination of the spores of lichens, a, ripe ascospore of Megah 
ospora affinis ; &and c, successive stages of germination, seen in optical section; 
d, still later staue of germination, seen in perspective, e, beginning of germination 
of ascospore otOchrolechia imllescens ; f, the same at a much later stjige, show- 
ing the mauy young hyphae, much less magnified, g, half of an ascospore of Per- 
tusaria centhocarpa ? seen in optical section, showing the pores in the endospoi-e 
through which the hyphse piss out. The exospore is shaded in the figure. /X 
190, the others X 390.— After De Bary. 

cate the truth of the theory that they are the male sexual 
elements ; on the other hand, their analogies to the similar 
organs of Helvellacem and Pyrenomycetes point rather to 
their conidial nature. 

Still other cavities (pycnidia) occur, in which spore-like 
bodies are found, differing in size and other characters from 
the spermatia. 



300 



BOTANY. 




Fio;. 206.— Vertical section of a 
small portion of the th alius of Col- 
lema Jacobcefolium,, showing the 
colorless* branching and jointed hy- 
phffi, the Nostoc-like gonidla, and a 
speimagoninm, from which sperma- 
tia are escaping. Magnified.— After 
Tulasne. 



398. — Until Stahl's researches* showed the existence of 
sexual organs in CoUema, they were entirely unknown among 

lichens. He discovered, deeply 
imbedded in the tissue of tJie 
plantj an organ composed of a 
spirally coiled hypha- branch, and 
a Ycrtical septate portion, which 
rises to, and projects above, the 
surface ; the spirally coiled por- 
tion he called the ascogonium, 
and the vertical portion the tri- 
chogyne. The whole he regarded 
as a species of carpogonium (Fig. 
207, A, c, and d). He observed 
spermatia adhering to the pro- 
jecting portion of the tricho- 
gyne ; some of these united them- 
selves to the trichogyne by means of a tube" {C, Fig. 207). 
The result of this coalescence was the withering and disap- 
pearance of the 
cells of the tricho- 
gyne, and the 
growth and devel- 
opment of the as- 
cogonium. The 
latter process takes 
I^lace as follows : 
'' The cells of the 
ascogonium first of 
all increase in size, 
and then undergo 

-, . . . Fig. 207.— Sexnal organs of Collema microphyllvm. A, 

division ; as a re- section of thallns; rt, a, hyphaj; b,b, the Nostoc-like 
If -P +1^' +V. gonidia ; c. ascogonium ;(?, the exserted trichogyne. B^ 
suit 01 tniS, tne the spermatia, &, surrounding the exserted trichogyne, a. 
Qm'ral Qwann-nvYionf ^' coalescence of a spermatium, b, with trichogyne. a.- 
bpirai aiiangement ah the figures magnified, B and (7 much more than A.— 

of the cells be- ^ft^^^stahi. 

comes less and less conspicuous, for the cells gradually sepa- 

* " Ueber die Geschleclitliclie Fortpflanzung der Collemaceen," 1877 
(On the Sexual Organs of the Collemaceae). A brief synopsis of Stahl's 
results appeared in the Qr. Jour, of Mic. Science, October, 1878. 




LIOHEl^ES. 301 

rate from one another. Whilst these changes have been 
taking place in the ascogoninm, it has become invested by a 
dense felt-work of hyphse, formed by the active growth of 
the hyphse of the thallus. From this investing layer hyphae 
grow inward between the separating coils of the ascogo- 
nium, and bear paraphyses^ which form the rudimentary 
hymenium. At the same time outgrowths have been 
formed from the cells of the ascogoninm, which either are 
asci, or grow into liyphal filaments, which bear asci as 
lateral branches. The asci, whether derived directly or in- 
directly from the cells of the ascogoninm, come to lie in the 
hymenium among the paraphyses. '' Thus the apothecium 
is partly developed from the carpogonium, and partly from 
the hypha^ of the thallus, agreeing in this with what is now 
known to be the mode of formation of the corresponding 
parts of some, at least,«of the Helvellacem. 

Whether there are similar sexual organs in other lichens, 
is at present unknown ; probably, when discovered, they will 
be found to bear some resemblance to those of Gollema, just 
described ; but it is altogether likely that, instead of fertili- 
zation taking place by means of free male elements (sper- 
matia), it will be shown to be more nearly like that now 
known in Peziza or Ascoholus. 

399.— The Gonidia. The gonidia of lichens are of so 
much importance that they demand a somewhat extended 
notice. As above stated (paragraph 392), they are green or 
greenish cells, or rows of cells, wliich occur either distributed 
irregularly through the tissue of the lichen-thallus (the ho- 
moomerous lichens), or in different layers or regions (the 
heteromerous lichens). These green bodies are of different 
forms in different groups of lichens, while in nearly related 
species they are often exactly alike. They may consist of 
isolated cells, or groups of cells, as in most fruticose or folia- 
ceous lichens {e.g., Physcia, Fig. 202, Stida, Fig. 201, 
Sphceropliorus and Usnea, Fig. 208), while, on the other 
hand, they may be made up of rows or chains of cells 
{e.g., Lecanactis and Gr aphis, Fig. 209, Mallotkim, Fig. 
210, and Collema, Figs. 206 and 207). They are known to 
reproduce by the division (fission) of their cells, and, in 



302 



BOTANY. 



some cases at least, when free from the lichen-thallus, by 
the production of zoospores. 

Their connection with the hyphan is sometimes by the 
j)rolongation of a short branch from the latter, which passes 
to each gi^nidial cell (Fig. 208) ; in other cases the connec- 
tion is with one cell of a row, as in Plectospora,'^ where the 
connection may be with the terminal cell of the row, or with 
any of the intermediate ones ; in either case, the cell to 
which the hypha- branch is attached is considerably larger 
than the others in the row. Schwendener describes} a con- 




FiG. 208. 



Fig. 



Fig. 208.— Gonidia of different lichens, a to 6, of Parmelia tiliacea, showing a, &, 
and e, the attached hyphse, x 390 ; /, of Usnea barbata, with attached hypha, X 
700 ; g, of Sphce^^ophorus globiferus, with attached hypha, x 390. — After De Bary and 
Schwendener. 

Fig. 209.— Gonidia. a, a, of Lecanaetis illecebrosa ; b, b, of Graphis scripta.— 
After De Bary. 

nection which he has seen in certain gelatinous lichens, in 
which two and three short branches pass off from the same 
hypha, and unite with the cells of one gonidial chain, 
TreubJ confirms Schwendener's statement, saying that he 



* See De Bary's " Morpliologie und Physiologie der Pilze, Flechten," 
etc., p. 264. 

f " Die Flecliten als Parasiten der Algen," 1873. 

X Dr. Melcbior Treub, " Onderzoekingen over de Natuur der Liclie- 

nen," 1873. 



LIGHENE8. 



303 



ht-iS '^ succeeded many times" in finding gonidia so connected 
to the hypliae by more than one branch. 

400. — With regard to the origin of gonidia, Fries asserts 
that the hypha-branches swell up at their ends, become glob- 
ular, and, after a while, filled Avitli green contents.* He, 
however, does not speak of any observations of his own upon 
which he bases his statement. Berkeleyf likewise regards 
them as developed from the mycelium, but made no observa- 
tions which can be considered conclusive. Speerschneider's 
observations, J in 1853 to 1857, along with those of Bayr- 




Fig. 210.— Mallofium (or Lppfngium) HUdenbrandn. a, vertical section through the 
thallus, u, the under side, x 190 ; b, portion of a very thin section near the under 
side, showing three gonidia chains, two hyphse, a portion of the lower limitary tissue, 
and two large and several small hairs, which are organs of attachment, x 390.— After 
De Bary. 

lioffer,§ some years earlier, appear to be, in reality, the ones 
upon which the view that gonidia develop from the hyphse 
depends ; their statements appear to have been accepted and 
repeated by lichenologists without suJBficient inquiry. The 
other errors of observation and interpretation made by these 
observers render their testimony upon the question of the 
origin of the gonidia of doubtful value. Schwendener, in 



* " Liclienograpliia Scandinavica," 1871. 

f " Introduction to Cryptogamic Botany," 1857, 



:j: In Botanische Zeitung, 1853, 1854, 1855, 1857. 

8 " Einiffes iiber die Liclienen und deren Befruclitunsf, 



1851- 



504 



BOTANY. 



reviewing the subject, affirms that the actual development of 
a gonidium from the end cell of a hypha has not been ob- 
served. Njlander even goes so far as to declare that in no 
case do the filaments themselves give birth to gonidia^ but 
that they "have their origin in the parenchymatous cortical 
cells which are observed on the prothallian filaments of ger- 
mination."* 

401. — The recent observations of Dr. Minks, f if con- 
firmed, will put to rest the question as to the origin of go- 
nidia. He studied the small green cells sometimes called mi- 
crogonidia, and makes the announcement that they originate 
in the interior of the cells of every portion of the lichen- 
thallus, viz., the cortical and medullary cells, the paraphy- 

ses and young asci, and 



^°o%iX 




even the spores and 
spermatia. The proto- 
plasm in the cells forms 
an axial column, which 
becomes broken up into 
rounded bodies of a pale 
greenish color ; these 
finally become covered 
by cell-walls, and after- 
ward escape from the 
mother- cell as free mi- 
crogonidia. He asserts 
that intermediate forms of all degrees are to be met with be- 
tween microgonidia and gonidia. Dr. Muller,in making simi- 
lar observations, arrived at the same conclusion^ as to the 
origin of the microgonidia. 

The third view as to the origin of gonidia is so intimately 
connected with the question of the real nature of the gonid- 
ium and its functional relation to the hj^phse, that it can 
only be explained by taking these into consideration. 



Fig. 211.— Soredia of Usnea barbata. A, sore- 
dium, consisting of one gonidium covered witti 
hyplise ; B, of many gonidia formed by division ; 
C, the gonidia separated by hypli?e ; D and E, the 
soredia developing into new lichen plants. X 
500.— After Schwendener. 



*Iu Flora, 1877, p. 256, as quoted in Benue Mycologique, p, 4, 1879 
and in "Grevillea," 1879, p. 91. 

f For accounts of these observations see Flora, 1878, Revue Mycolo- 
gique, 1879, and American Journal of Scierice and Arts, 1879, p. 254 

X Flcra. 1878. 



LICHENE8. 303 

402. — The gonidia sometimes escape from the thallus of 
the hchen surrounded with a few hyphse (Fig, 211) ; these 
are called soredia. Under favorable circumstances they may 
give rise to new lichens, and hence have been looked upon 
by some as asexual organs of reproduction. Soredia arC; 
iiowever, rather of the nature of buds or gemmae, which, 
under certain circumstances, become detached. Their pro- 
duction is, to a certain extent, accidental, 

{a) 1. The Nature of Gonidia. Until recently, tlie gonidia of 
lichens Lave been generally regarded as accessory reproductive bodies. 
De Bary,* however, in studying the Collemaceae, and noting the remark- 
able resemblance between their gonidia and certain algae, came to the 
following conclusion: " Either the lichens in question are the perfectly 
developed states of plants whose imperfectly developed forms have 
hitherto stood among the algae as the Nostocaceae and Chroococcaceae ; 
or the Nostocaceae and Chroococcaceae are typical algae which assume the 
form of Collema, Ephehe, etc., tlirough certain parasitic Ascomycetes 
penetrating into them, spreading their mycelium into the continuously 
growing thallus, and becoming attached to their phycochrome-contain- 
ing cells." Schwendener,f Reess,:}: and Bornetg have taken up the 
second theory in the above alternative, and extended it to all lichens, 
Schwendener, who first made the definite statement of the theory, holds 
that every lichen is a colony composed of a parasitic fungus on the one 
hand, and a number of low algae on the other ; the former, which pro- 
duces the asci, spermatia, and other reproductive bodies, is nourished 
by the latter, which constitute the gonidia of the lichen. 

A lichen, according to this view, is not an individual plant, but rather 
a community made up of two kinds of individuals ; and the gonidia are 
only the temporarily imprisoned algae, which furnisli nutriment to the 
parasitic fungus. The fungus parasite does not differ in any essential 
character from those of the two higher orders of the Ascomycetes. 
Leville, in speaking of lichens and the ascomycetous fungi, said,| 
" I find the distinctions to be so trifling, that I have always regretted 
that these vegetables should not be placed under one head. The para- 
physes, tliecae (asci), and spores are identical." 

* " Morphologie und Physiologie der Pilze, Flechten, und Myxomy 
ceten,"1865, p. 291. 

f Dr. S. Schwendener : " Untersuchungen liber den Flechtenthallus," 
1868, and " Die Algentypen der Flechtengonidien," 1869. 

X Professor Max Reess : '* Ueber die Entstehung der Flechte Collema 
glaucescens," etc , 1871. 

§ Dr. E. Bornet : " Recherches sur les Gonidies des Lichens," 1873. 

II A letter to Decaisne, as given in Le Maout and Decaisne's " Traite 
Generale de Botanique," 1868. 



306 BOTANY. 

2. Scliwendener has shown* that the gonldia may be referred to well, 
known groups of aloae, some of which belong to the Zygophyta, while 
others belong to the Protophyta. Thus the gonidia of Collema, Lepio- 
gium (including Malloiium), Pelligera and some other genera, are iden- 
tical with Nostocacese ; those of Omp]i,alana and others, with Chroo„ 
coccacege ; those of Orophis, Veirucm^ia, etc., with Chroolei)idese (re- 
lated to (JonfevGci and Cladophora) ; those of Usnea, Cladonia, Physcia, 
Parmelia, and most higher lichens with Palmellacege. The gonidia of 
some other lichen gerera are referred to still other alga groups. 

3. When gonidia nre dissected out from the lichen-thallus they are 
capable of independent existence ; and there can be no doubt that (as 
De Bary intimated) many of the forms regarded as algse are identical 
with gonidia.f With these facts before us, it can scarcely be doubted 
that the mode of origin described by JSpeerschneider and Bayrhoflfer is 
incorrect. There cannot now be shown any good evidence that the go- 
nidia develop from tlie hyphse with which they are seen to be in contact. 
The connection between hyphse and gonidia is doubtless one which takes 
place after the origin of the latter. The two remaining views — i.e., 
Schwendener's and Minks' — agree upon this point, and in both the idea 
of a genetic connection between gonidium and the hypha-filament in 
contact with it is rejected. These two theories, however, differ radi- 
cally in this, that while on the one hand the gonidia are regarded as 
true liclien-cells, on the other they are held to be algge belonging to en- 
tirely different thallophytic groups, 

4. It must at once be evident to any one tliut the actual relation of 
the hyplial portion of the lichen to the gonidia is the same whether the 
origin of the latter be, as asserted by Minks, within the hyphse, or en- 
tirely independent of them, as maintained by Scliwendener. Any con. 
nection which subsists between these two can be, under the circum- 
stances, of only one kind, namely, that of a greater or less degree of 
parasitism. It makes no difference to show that the gonidia are derived 
from the hyphse themselves, for they are (it is said) set free after their 
formation in the mother-cell ; now any subsequent connection of these 
green cells with the hyphse cannot possibly have any other meaning 
than that the latter derive nourishment from them. The only differ- 
ence between the two theories may be expressed in this way : according 
to the one, the imprisoned slaves which furnish nourishment for the 
liyphal master are members of entirely different groups of the vegetable 
kingdom ; while according to the other, the slaves are the offspring of 
the hyphal master which imprisons them. In the first the gonidia are 



* " Die Algentypen der Flechtengonidien," 1869. 

f This was long since shown by Itziiisohn — Botanische Zeituhg, 1854, 
by Hicks — Qr. Jour, of Mic. Science, 1861 , and by Famintzin and Baranet- 
sky — Botanische Zeitung, 1867 ; Nylander also arrived at the same con- 
clusion with regard to the gonidia of Collema — Flora, 1868. 



LICHENE8. 307 

slaves not at all related to the hyplise ; in tlie otlier tliey are produced 
by them, and after a brief period of freedom are fastened upon, and 
compelled to do service for the liyplise which produced them. 

It is impossible to decide between these two theories until further in- 
vestigations shall determine the truth or falsity of Dr. Minks' state, 
ment as to the origin of microgonidia. It must, however, be said, that 
the view which appears to be most in accord with what we now know 
of plants, is that taken by Schwendener. 

(h) 1. Cultures of lichens have been made by many observers, 
especially by Bornet, Reess, and Treub, The latter made an extended 
series, from which the following details of methods are condensed. 
Spores may be secured for germmation by placing freshly gathered 
lichens upon plates covered with well-moistened glass slips, and keep- 
ing them under a bell-jar for from twelve to twenty-four hours, at the 
end of which time a number of spores will be found on the slides. 

3. The spores may be left upon the slides and allowed to remain in a 
moist atmosphere, as in a bell-jar. Others may be placed upon very 
thin pieces of the bark upon which the lichens naturally grow. Still 
others may be made to grow in the presence of a small quantity of the 
ash of the same species of lichen. 

3. A too copious supply of moisture is unfavorable to the successful 
germination of the spores. If the conditions are favorab'e germination 
will begin in from two to eight days. In about a month after sow- 
ing, the protoplasm of the spore becomes in great part used up in the 
formation and elongation of the germinating filaments. It always hap- 
pens that the growth of the liyphse from the spores ceases soon after the 
exhaustion of the protoplasm, unless the hyplise come in contact with 
algse of the proper kind, or with gonidia, 

4. An interesting culture may be made by repeating Bornet's exper- 
iment, as follows: He placed on fragments of bark, previously boiled 
to kill all otlier germs, and also on pieces of limestone freshly broken, 
a layer of Protococcus viridis scraped off of a damp wall, and to this 
added the spores of Theloschistes parieiinus. In about a fortnight the 
hyphae were seen to be large and ramified ; wherever they came in 
contact with cells of the Protococcus they adhered either directly or by 
means of lateral branches. Bornet made at the same time parallel cul- 
tures, without, however, bringing the germinating spores into proximity 
to Protococcus ; the growth was much less, and in no case did he get 
any evidence that the hyphae themselves formed gonidia. 

5. Treub modified Bornet's culture by using, in some of his experi- 
ments, the artificially isolated gonidia of one species of lichen — for ex- 
ample, of some species of Ramalina — and the spores of a different one, as 
Theloschistes parieiinus. He also use^d glass slides for his cultures, 
whether with gonidia or free algae, taking the precaution, however, to 
allow the drop of water in which the spores and gonidia were placed 



308 



BOTANY. 



to completely evaporate before placing in the moist chamber. By tab- 
infr precautions to keep out moulds, by supplying the moist chamber with 
air passed through one or two plucrs of cotton-wool, he succeeded in 
continuing the orrowth of the hypb* for three mouths, at the end of 
which time the algae were surrounded by a good number of branches 




Fig. 212. Fia. 213. 

Fie. 212.— Usneabarbn fa, nat. size, a, a, apothecia ; /, disk by which it is attached 
to the bark of a tree.— After Sachs. 
Fig 2\S. -Sticta pulmonacea, nat. size, a, a, apothecia.— After Sachs. 

of the hypliae, many of which had firmly attached themselves to the 
cells of the algse. 

(c) The classification of lichens is by no means settled. 

The arrangement which is followed in this country is that of Profes- 
sor Tuckerman.* He divides the order into five tribes, as follows: 

Tribe I. Parmeliacei. 

Apothecia rounded, open, scutelliform, contained in a thalline exciple. 

Family 1. TJsneei. Roccella, Ramalina, Dactylina, Cetraria, Emr- 
nia, Usnea (Fig. 212), Alec'ona. BocceUa Hndoria and other species cv 
the genus furnish the dye known as orchil, and chemical test "litmus. 
Cetraria islandiea, the Iceland moss, is used both as a food and a medi- 



* Edw. Tuckerman : " Genera Lichenum ; An Arrangement of North 
American Lichens," 1872, and " Synopsis of N. A Licliens," 1882. 



LIGHENES. 



309 




Fig. 'i^H.—Collema pulposum, 
slightly magnified, showing the 
apothecia.— After Sachs. 



cine. Species of Evernia are sometimes used for furnishing yellow 
dyes. 

Family 2. Parmeliei. Speei schneidera, Theloschistes, Parmelia 
Physcia (Fig. 202), Pyxiiie. From Parmelia parietina fine dyes have 
been obtained. 

Family 3. XJmbilicariei. TlmUlicOr 
ria. 

ram.ily 4. Peltigerei. Sticta (Fig. 
213), Nephroma, Peltigera, Solorinn. Stic- 
ta pulmonacea was formerly used in medi- 
cine, but it has fallen into disuse, except- 
ing with quacks. 

Fam.ily 5. Pannariei. Heppia, Pan- 
naria. 

Family 6. CoUemei. Ephebe, Licli- 
ina, Synalissa, Omphalaria, Collema (Fig. 214), Leptogium, 
thy ria. 

Fam.ily 7. Lecanorei. Placodium, Lecanora, Rinodina, Pertusor- 
ria (Fig. 215, G), Gonotrema, Dirina, Oyalecta, Urceolaria, Thelotrema, 

Oyrostomum. Lecanora tarta- 
rea lurnish-3s a dye, and L. 
esculenta, of Asia Minor, sup- 
plies a valuable food ; it is 
sometimes " carried up by 
whirlwinds and deposited aftei 
traversing the air for many 
miles, giving rise to stories of 
the miraculous descent of food. 
A few years since, in a time of 
great scarcity at Erzeroum, a 
shower of these lichens fell 
most oi)portunely, to the great 
relief of the inhabitants."* 

Tribe 11. Lecideacei. 

Apothecia rounded, open, pa- 
telliform, contained in a proper 
exciple. 

Family 1. Cladoniei. 8te- 
reocaulon, Pilophorus, Cladonia. 
Gladonia rangiferina is the 
" Reindeer moss " of the Arctic- 
it furnishes a valuable food to the reindeer. 




Fig. 215.— J., Crraphis elegans on a piece of 
a twig of the holly ; B, the same slis^htly mag- 
nified ; C, Pertusaria Wulfeni, slightly mag- 
nified, on a piece of old wood.— After Sachs. 



regions 



* Berkeley : '* Introduction to Cryptogamic Botany," p. 883. 



310 BOTANY. 

Family 2. Coenogoniei. Ccenogonium. 

Family 3. Lecideei. Bceomyces, Biatora, Heterothecium^ Lecidea, 
Buellia. 

Tribe III. Graphidacei. 

Apotliecia of various forms, frequently lirelliform, in a proper ex- 
ciple. Thallus crustaceous. 

Family 1. Lecanactidei. Lecanactis, Plaiygrapha, Melaspilea. 

Family 2. Opegraphei. Opegrapha, Xylographa, Oraphis (Fig. 
215, A). 

Fam.ily 3. Glyphidei. Cliiodecton, GlypMs. 

Family 4. Arthoniei. Arthonia, Mycoporum. 



Tribe IV. Caliciacei. 

Apotliecia turbinate-lentiform or globose, frequently stipitate, mar. 
gined by a proper exciple, the disk breaking up into naked spores, 
which form a compact mass. 

Family 1. Sphseropliorei. SpJimropTiorus, Acroscyphus. 

Fam.ily 2. Caliciei. Acolium, Calicium, Goniocyhe. 

Tribe V, Verrucariacei. 

Apothecia globose, in a proper exciple, becoming pertuse with a pore. 

Family 1. Endocarpei. Endocarpoji, Normandina. 

Family 2. "Verrucariei. Segesiria, Staurothele, TrypetheUum, 8a- 
gedia, Verrucaria, Pyrenula, Pyrenastrum, Strigula. 

(d) Fossil lichens are extremely rare, only a few Tertiary species of 
modern genera being recorded. 

403.— Order Uredineae. — The Uredinese are related to the 
foregoing orders of the Ascomycetes^ and probably should be 
grouped with them. They are all parasitic in habit, and the 
vegetative portions of the plant-body are greatly reduced, 
leaving but little more than the organs of reproduction. 
Their life-history is but imperfectly known, and nothing is 
yet known as to their sexual organs. They are generally 
polymorphic — that is, they assume, in their production of 
various kinds of spores, such apparently distinct forms, that 
these have frequently been mistaken for distinct plants. 

404. — So far as made out, the life-history of the Uredineae 
appears to be about as follows : In the spring there appear in 
the tissues of the leaves of various plants dense masses of 



UREDINE^. 



311 



hjpliae, wliicli penetrate between the cells, causing the leaves 
to become usually much thickened and distorted in those 
parts which are infested with the parasitic growths. Oc- 




Fig. 216.— Several stages of Puecinia graminis. A, part of a vertical section of a 
leaf of the Barberry {Berberis vulgaris), with a young unopened ascidium fruit ; u, 
epidermis. /., section of a Barberry leaf, natural thickness at X, greatly thickened 
from h toward y ; u, epidermis of the under surface ; o, of the upper surface ; p, 
unopened aecidium fruit ; «, a, a, opened secidium fruits ; sp, sp, spermagonia, //., 
amass of teleutospores on a leaf of Couch-grass (Triticum repens) ; e, the ruptured 
epidermis; b, sub-epidermal fibres of the grass leaf . ///., three uredospores, -wr, 
with one teleutospore, t; sh, siib-hymenial hyphee. All highly magnified.— J. and I. 
after Sachs ; //. and ///. after De Bary. 

casionally these hyphao are found in other parenchymatous 
parts besides the leaves, as the petioles^ young stems, and 
even the flowers and fruits. After a short time there form 



312 BOTAXY. 

globular masses, which lie in the parenchvma just beneath 
the epidermis ; these are composed at the bottom of an hyme- 
nium-like layer of sterigmata (shown in Fig. 216, A and I, as 
a layer of elongated cells). Each sterigma produces a chain 
of cells, which are at first many-sided from mutual pressure, 
but afterward sj^herical. By their growth these globular 
masses finally burst through the epidermis (Fig. 216, /., 2^), 
and soon afterward, by tlie rupture of the thin investing 
layer of cells (peridium), they become opened and cup- 
shaped (Fig. 216, /., a, ctf a). The now rounded cells are set 
fi'ee as large yellow conidia (or gecidiospores). At one time 
this stage was supi^osed to constitute a distinct j^lant, and it 
received the generic name of Mcidium, hence it is still 
known as the ^cidium stage. 

In many (if not all) cases there is a second kind of repro- 
ductive organ present, resembling in some resjoects the ^cid- 
ium fruits just described. These are smaller flask-shaped 
cavities, which are filled with slender hair-like filaments (Fig. 
216, Z, sp, sp) ; these are the spermagonia, and they pro- 
duce, by the breaking up of the filaments, numerous ex- 
ceedingly small oblong bodies, the spermatia. The ftmction 
of these is not known : at one time it was supposed that they 
were the male reproductive bodies, but it is very doubtful 
whether they are of this nature. 

405. — The conidia (aecidiospores), when they fall upon the 
leaves of the pro^^er host plant, germinate, and j^enetrate 
the stomata, thus reaching the leaf 23arenchyma, where a dense 
mycehum is formed. TTpon this are formed, within a short 
time, stalked spores (uredospores. Fig. 216, ///., ur^ ; these 
finally burst through the epidermis, and form orange-colored 
spots upon the leaves. The uredospores fall off very easily^ 
and germinate quickly, giving rise immediately to another 
mycelium (Fig. 21 T, I)), which produces uredospores, which 
may, in turn, give rise to new mycelium, and so on indefi- 
nitely. The function of the uredosjDores is clearly the quick 
rei:>rodtiction of the fungus. 

406. — After the production of uredospores has continued 
for some time, the same mvcelium gives rise to stalked, thick- 



UBEDINE^E. 



313 



walled bodies {teleutosi^ores,'^ or pseudo-spores), which are 
one, two, three, or many-celled (Fig. 216, ///., t). Like 
the uredospores, the teleutospores are produced beneath the 




Fig. 217. — Pwccinia graminis. A, germinating teleutospore, t, witli promycelium 
forming the sporidia, sp. B, similar promycelium, witli sporidia. C, a sporidium, 
sp, germinating on a jjiece of the under side of a leaf of the Barberry, the mycelium, 
i, penetrating the epidermis. D, a germinating uredospore, u, fourteen hours after 
being placed on the leaf of a grass, forming a branched mycelium. Highly magnified 
—After Be Bary. 

epidermis of their hosts, which in their growth they burst 
through, and appear as small rounded clusters (sori), or more 

* From tlie Greek Ts/^evrij, end ; so named because it is generally ^lie 
last reproductive body of these fungi produced in tlie season. 



314 



BOTANY. 



or less elongated lines. In color they are almost invariably 
brown or nearly black, in marked contrast to the reddish yellow 
(orange) uredosporcs. In some cases they are joroduced early 
in the season, but in the greater number of cases they appear 
in the autumn, and then remain through the winter upon 
the dead stems of their host plants. The following spring 
the teleutospores germinate by sending out a jointed filament 
{i\\Q promycelmm) fi'om each cell ; this grows to several times 
the length of the teleutospore, and then sends out a few lateral 
branches, each of which bears a small terminal cell, a sporid- 
ium (Fig. 217, A and B, and Fig. 218). The sporidia are 

extremely minute, and, as a 
consequence, are carried about 
from place to place in the wind 
with great ease. When they 
fall upon the joroper plant, each 
sporidium sends out a minute 
filament, which perforates the 
epidermis-cells, and from these 
passes into the leaf parenchy- 
ma, where it develops into a 
mycelium (Fig. 217, C). From 
this last mycelium the aecidium 
'fruits first described develop. 

{a) The life-cycle, as above given, 
is apparently abridged in some of 
the Uredinese. The secidium and uredo stages are merged into one, or 
either the first or second is entirely wanting. This appears to be the 
case in Phragmidium, Oymnosporangium, Melampsora, etc. 

(6) With most of tlie species it happens that the secidiospores (conidia) 
develop upon one host, and the uredospores and teleutospores upon an- 
other. This alternation, which is termed by De Bary hetermcism, has 
added very much to the difficulty of the study of these fungi, and pos- 
sibly the apparent abridgement of the life-cycle above mentioned may 
in some instances be only an obscure heteroecism. 

(c) Thus far the sexual organs have not been discovered ; Sachs* 
argues that they must precede the secidiospores, and that the aecidium 
fruit is in all probability the result of a sexual act. He bases his argu- 
ment upon the law that the rep rod active organs of most complex struc- 




Fig. 218.— Germinating teleutospore 
of Pucemia 3Iolini(B, showing promy- 
celium and sporidia.— After Tulasne. 



Lehrbuch der Botanik," 4te Auflage, 1874, p. 331. 



UEEBINE.E. 



315 




Fig. 219. — Young teleuto- 

spores of PJiragmidium mu- 
cronatum, showing the an- 
gular masses which eventu- 
ally develop into the cells 



ture follow or proceed from a sexual act ; and maintains that the aecid- 
ium fruit is more complex in structure than any of the others. He 
further says, " Tliea3cidium fruit corresponds, then, to the perithecium of 
the Ascomycetes, the secidiospores to the ascospoies ; and the uredo 
spores and teleutospores are evidently differ- 
ent forms of conidia." It is very doubtful, 
however, whether future investigations will 
prove the correctness of Sachs' surmise. It is 
much more probable that the teleutospores re- 
sult from a sexual act, and that they are to 
be compared to the asci of the Ascomycetes. 
The teleutospores are possibly reduced asci, 
containing one or more large ascospores ; in 
some cases— e.p'., in Pnccinia Helianthi — an 
outer investing membrane can be distinguish- 
ed after treatment with potassic hydrate, 

while in Pucciriia {Uropyxis) Amorphce there of "the mature teleutospore, 
is " a deciduous outer coat,"* which contains ^'^^^^ magnified, 
the double spore, and (when moistened) a mass of jelly. In both these 
cases the membranous covering closely resembles an ascus which fits 
closely over its contained double spore. In the genus Phragmidium 
(Fig. 220), especially in young teleutospores, the resemblance to asci 
and ascospores is still more striking ; the so- 
called " cells" of the teleutospore originate as so 
many separate masses in the interior of a large 
ascus-hke membrane (Fig 219) ; in their further 
development the cells become large, and at last 
fill up the whole cavity, and then have the ap- 
pearance of Fig. 220. 

The resemblance of the teleutospores to re- 
duced asci is close enough to make it probable 
that sexual organs resembling those of Asco- 
mycetes will be found to precede them. This 
is rendered the more probable from the resem 
blance of secidinspores, spermatla, and uredo- 
spores to the conidia, sperraatia, and stylospores 
of various Ascomycetous fungi. f 

(d) The principal genera in this order are 
Uromyces and Melampsora with one-celled te- 
leutospores, Puccinia and Gymnosporangium, 
with two cells, and Phragmidium (Fig. 220) with 
many cells. Many species are known, there being in the genus Puo 




Fig. 220 —Mature teleu- 
tospores of Phragmidimn 
bulbosum. Highly magni- 
fied.— After Cooke. 



* So described by Berkeley : " Introduction to Cryptogamic Botany," 
1857, p. 325. 

f Some of these resemblances were pointed out many years ago by 



31G BOTANY, 

cima alone from forty to fifty species in the United States. They at 
tack many species of Phanerogams, but are scarcely known as para 
sites upon Cryptogams. The first stage was long known as the genus 
JEddiam, and under this many supposed species were described, and 
this is still the case in all English systematic works ; in the same way 
the second stage gave rise to the supposed genera, TIredo, TricJiohasis, 
etc., and even these are, to a great extent, retained in the ordinary 
books, although their autonomy was long since disproved. 

{e) One of the best known species of this order is that which appears 
upon wheat, oats, and some other cultivated grasses, producing, or 
rather being, the disease known as Rust {Pucci?iia graminis). It ap- 
pears in the spring upon the leaves of the Barberry, developing there 
the secidiospores (conidia), and constituting what for a long time has 
been known as the Barberry Cluster-Cups, or Barberry Rust (Fig. 216, 
A and L). Later in the season, and usually after the Cluster-Cups 
have entirely disappeared from the Barberry, the uredo stage begins 
to make its appearance, first upon the leaves, and then upon the stems 
of the wheat, oats, etc. ; at first it may be detected by the pale yellow- 
ish or whitish spots on the leaves ; these mark the places where the 
uredospores are b( ginning to form beneath the epidermis. Within a 
few days the uredospores (Fig. 216, III., ur) break through the epider- 
mis and expose long lines of the orange-red spores. By the quick ger- 
mination of the uredospores, first produced, the fungus is greatly 
increased, so that frequently the host plant is destroyed before reach- 
ing its maturity. This stage is known popularly as the Red Rust of 
wheat, oats, barley, and other similar grasses. Still later in the season, 
and usually after the ripening of the host plants, the dark-colored 
teleutospores (Fig. 216, //.) appear in long black lines, sometimes upon 
the leaves, but more frequently upon the stems, and in ordinary 
cases upon the uncut part of the stem, viz., the " stubble." This stage 
is known as the Black Rust. The teleutospores remain upon the dead 
stems through the winter, and in the following spring germinate and 
produce sporidia, which give rise to a mycelium in the Barberry 
leaves (Fig. 217, A, B, and C). 

De Bary,f by placing the teleutospores upon young leaves of the 
Barberry, succeeded in producing the secidium stage, thus proving 
Barberry rust to be but a stage of Pvccinia graminis. Similarly it 
has been shown that the eecidiospores of Barberry rust will not grow 
upon Barberry leaves, but that when placed on a leaf of wheat, oatSj 

Frederick Currey. In a paper" On the Affinities of theUredineas," pre- 
sented to the Iowa Academy of Sciences, May, 1878, I pointed out that 
the structural similarity of TJredinese and Ascomycetes rendered it 
probable that the sexual organs of the former preceded the teleutc 
spores. I did not then know of Currey 's paper. 
\ Published in Monatsher. d. Berl. Acad., 1865. 



IJSTILAGINE^, 317 

barley, etc., tliey send out filaments, wlicili pass tlirougli tlie stomata. 
and give rise to a mycelium, wliicli, in about a week, produces uredo- 
spores. 

(/) Uredineae are easily obtained for study in either the first, second, 
or third stage. In most species the secidium stage occurs in spring or 
early summer, the second in spring or summer, and the tlii-rd in the 
autumn ; in some species, however, the teleutospores are produced in 
the spring, as in Oymnosporangium and Puccinia Anemones. 

{g) The sporidia may be obtained by placing pieces of grass stems 
containing teleutospores in a damp atmosphere, after soaking for a few 
hours in water. The teleutospores should be freshly taken in most 
cases from those which have remained upon the stems out-of-doors 
during the winter. 

407.— Order Ustilagineas. The jHants wliicli compose 
this order are all parasites living in the tissues of Phanero- 
gams. Like the Uredinese, the Ustilaginese send their my- 
celium through the tissues of their hosts, and afterward 
produce spores in great abundance, which burst through the 
epidermis. Tliere is, however, in many respects a greater 
simplicity of structure in the plants of the present ordei 
than in the Uredineae, and this has induced some botanists 
to doubt their relationship to the last-named order ; how- 
ever, it appears that the simplicity is one due rather to 
degradation than to any essential difference in structural 
plan. 

408. — The mycelium of the Ustilaginese is well defined, 
and consists of thick-walled, jointed, and branching hyphae, 
which are generally of very irregular shape.* The hyphae 
grow in the intercellular spaces, as well as within the cell 
cavities of their hosts. They send out suckers (Jiaustoria), 
which penetrate the adjacent cells much as in the Perono- 
sporeae ; these are more abundant in the compact tissue of 
the nodes of stems than in the long-celled tissue of the in- 
ternodes. The mycelium generally begins its growth when 
the host plant is quite young, and grows with it, spreading 
into its branches as they form, until it reaches the place 
of spore-formation. In perennial plants the mycelium is 

* The following account of the Ustilaginese is based upon an article on 
this order by Dr. A. Fischer von Waldheim, published in Pringsheini's 
"Jahrbiicher fur Wissen. Bot.," 1869. A translation appeared in the 
Transactions of the iV. T. State Agricultural /Society, 1870. 



318 BOTANY. 

perennial, the fungus reapi)earing year after year upon the 
same stems, or upon the new stems grown from the same 
roots ; in annuals it must obtain a foothold in the young 
plants as they grow in the spring. 

409. — The mycelium can be traced in the Monocotyle- 
dons often for long distances ; thus in the smut of Indian corn 
( IJdilago Maydis), at the time the spores are found in the 
distorted grains the hyphse have been detected at all inter- 
mediate points down to the lower internodes, and in the 
smut on wheat ( Ustilago carlo) they have been observed in 
every part of the plant, from the root through the stem to 
the inflorescence. In neither case, however, are the hyphae 
to be found in parts through which it is not necessary for 
them to pass in order to reach the point where the spores 
are formed ; thus they are usually not found in the leaves 
unless spores are formed in them. 

410. — The formation of spores appears to have some re- 
lation to the develoj3ment of the host plant, as they form 
only in certain parts of the latter, and are not produced 
until the growth of these parts has taken place. Thus in 
the Bunt of wheat {Tilletia caries) the spores are formed 
only in the young ovaries ; in the anther smut of the Si- 
lenem ( Ustilago antlierarum) the spores are formed in the 
young anthers ; in one of the smuts of the sedges ( Ustilago 
urceolorum) they form on the upper surface of the ovary, and 
in the smut of wheat, oats, etc., in the young flowers. In 
cases like these it is evident that the time of spore-forma- 
tion is dependent upon the development of the flowers of 
their host ; and if these are earlier or later in their ap^^ear- 
ance, the spore-formation will vary accordingly. In the 
smut of Indian corn ( Ustilago Maydis), on the other hand, 
the spore-formation may take place in other parts of the 
plant, as well as in the ovary ; thus it not infrequently makes 
its appearance upon the stems, and even upon the leaves. In 
Ustilago hypogcBa the spores are produced underground 
upon the root of the host plant [Linaria spuria), and in 
Ustilago ynarina, in the tissues of Scirpus parviilus, under 
water ; with these two exceptions, the spore-formation always 
takes place in parts above ground. 



USTILAQINEJE. 319 

411. — Immediately preceding the formation of spores 
the hyphse give rise to many branches, which differ much in 
appearance from the ordinary ones. This takes place in 
those parts of the host plant where the spores are afterward 
produced. These spore-forming hyphae are thicker than the 
vegetative ones, and are more gelatinous ; they are more or 
less granular, and they sometimes contain oil globules. 

412. — The spores are formed in Tilletia caries by little 
lateral branches budding out upon the spore-forming hyphse, 
and acquiring a pear-shaped outline ; they become thicker 
and more spherical, and each eventually secretes a dark, thick 
wall (Fig. 224, k' and h). When mature, the spores become 
free by the drying up of the attaching pedicel. In Ustilago 
the spore-forming hyphse break up their contents into 
spores, and in some cases — as, for example, in Ustilago 
Maydis — the process much resembles the formation of asco- 
spores in asci (Fig. 221). It frequently happens that the 
spore-forming hyplise fuse together on account of the gelat- 
inous nature of their envelopes ; when this takes place, the 
spores are formed in very irregular masses (Fig. 222,- h). 

In 8orosporium> Sa2)QnaricB this fusing takes place to so 
great an extent that the real nature of the process is greatly 
obscured. The spore-forming hyphse, which are very abun- 
dant, become curved at their extremities, and many of these 
twist themselves into a little ball, and are fused into a single 
gelatinous body, which eventually becomes a mass of spores. 
The real nature of the spore-formation is probably indicated 
by the "solitary spores," which appear singly upon those 
spore-forming hyphae which do not compact themselves into 
balls ; in these, the resemblance to asci containing single 
ascospores is striking (Fig. 223). 

413. — The spores, when ripe, have a double wall. The 
outer — the epispore — is thick, usually brown or black, some- 
times smooth, but frequently more or less rough by projec- 
tions, or marked by reticulations (Fig. 224, e). The inner 
wall — the endospore — is a delicate colorless membrane^ which 
protrudes through the ruptured epispore in germination. 

414 — The germination of the spores has been made out 



320 



BOTANY. 



for many of the species. In all which have heen examined 
the spore sends out a promycelium, which is generally short 
and jointed, and upon this several sporidia are produced, 
much as in the Uredineae.* In Tilletia caries the promyce- 
lium produces a tuft of slender branches (Fig. 224, h), whichf 



! 




Fig. 221. 



Fig. 222. 



Fig. 221.— Spore-formation in Ustilago Maydis. a, the end of a spore-forming hy- 
pha containing a row of young spores ; h, another spore-forming hypha, containing 
two young spores; c, a epore nearly ripe, still surrounded by the gelatinous mem- 
brane of the hypha. X 1800.— After Fischer von Waldheim. 

Fig. 222.— S[)ore-formation in Ustilago anfherartmi. a. an isola.^d gelatinous hy- 
pha, with the contents distinctly breaking up— at the lower end a portion not yet 
broken up ; b, anumher of gelatinous hyphfe fused into an irregular mass, showing 
the formation of m my spores ; c, a spore nearly ripe, still surrounded by the gelat- 
inous hypha memorane, also a young spore upon a lateral branch, a and c X 1800 ; 
h X 900.— After Fischer von Waldheim. 

Fig. 223.— Formation of "solitary spores" m Sorosporium Saponarice. a, hyphss 
with two young spores; b, aspoie at a later stage; c, hyphse with spores in differ- 
ent stages of development ; at c' a thin wall has formed around the contained pro- 
toplasm as in b ; at c'^ the wall is much thicker, and at &'^ it is still thicker, x 300.— 
After De Bary. 

have been seen to unite laterally by a kind of conjugation 
(not, however, of a sexual nature, in all probability) ; from 
these branches (called by some writers " secondary spores") 

* In 1883 Brefeld showed (" Untersuchungen uber die Hefenpilze") 
that the Ustilaginese are capable of perpetuating themselves for long 
periods, outside and independently of their host-plant in the excreta of 
herbivorous animals. The sporidia continue to multiply themselves 
by budding, after the manner of Saccharomyces. So greatly do these 
resemble the propagation of yeast cells that Brefeld has applied to 
them the name of "yeast spores" and " yeast colonies." ^Piowright. 
"British Uredineae and Ustilaginese.") 



USTILAQINE^. 



321 



there grow out small sporiclia^ wliicli germinate by sending 
out a slender hypha ; when this hypha comes in contact 
with the young host plant, it penetrates the walls of its 







Fig. 'H'^.—Tilletia caries, d, transverse section of an infected wheat-grain ; e, ripe 
spore ; /, the fir^t stage of germination ; g, tlie formation of a branching promyce- 
lium, with granular protoplasm in its upper end; h, the formation of slender 
branches which unite by a kind of conjugation ; the ends of these branches give rise 
somewhat later to very small sporidia, and when the.-e germinate very slender hy- 
phse are produced, which penetrate the epidermis as at i ; Tc'^ mycelium from the 
young ovary of the wheat— two small lateral branches are shown, from which spores 
will develop ; Tc, spores more fully developed.— t?, after CErsted ; e-h, after Tulasne, 
X 460 ; ir-h, after Kuhn, x 300. 

cells, and thus gains admittance to its interior, where it pro- 
duces a new mycelium* (Fig. 224, i). In Ustilago carljo the 

* This was first demonstrated by Kuhn: " Krankli'^lten der Kultur- 
gewaclise,"1859. Wolff's investigations ("Der Brand des Getreides," 
1874) show that only very young plants can be infected. 



322 BOTANY. 

promycelinm branches less frequently, and generally pro- 
duces from three to four sporidia. In few other cases than 
Tilletia caries is the mode of entrance of the fungus into 
the host plant known. 

415. — ^^0 sexual organs have yet been discovered. They 
are probably to be looked for just preceding the formation 
of the spore-bearing hyphse. The uniting of the hypha- 
branches in the germination of the spores of Tilletia caries 
(Fig. 224, li) has probably no sexual significance. 

{a) In tlie study of the mycelium of tlie Ustilaginege, tlie Lyplise 
iDay be made more distinct in tliin sections of the host plant by the 
ap[)lication of a solution of potassic hydrate. A similar effect is pro- 
duced by treating the specimen for some hours with thinned glycerine. 

(h) In the study of the spore development, the specimens must be 
examined in very early stages of the growth of ilie fungus. This can 
generally be done in the case of those species which affect the Gram- 
inese, by taking the afifected " suckers " or lateral branches of the host 
plant, after the spores are pretty well advanced on the main stem. 

(c) Upon the application of a solution of iodine, the contents of the 
young spores become yellow, indicating their protoplasmic nature ; 
treated with Schultz's solution, the contents become brownish yellow. 
The gelatinous membrane is not colored by the last-named reagent, 
showing that it is not cellulose ; but when treated with a solution of 
potassic hydrate, it is colored yellow, and in sulphuric acid it is dis- 
solved. 

{d) The ripe spores frequently require to be treated with reagents to 
bring out their structure. The endospore may be rendered visible by 
the application of sulphuric acid which makes the epispore more 
transparent ; in concentrated sulphuric acid the structure of the epi- 
spore is made much plainer; treatment with a solution of potassic 
hydrate causes the spore to swell up. 

{e) In the study of the germination of the spores, it is only neces- 
sary to place freshly gathered spores in a drop of water, or upon 
moistened earth, or in an atmosphere kept moist, as under a bell-jar. 
Germination takes place in the proper temperature (20° to 25° C, or C8° 
to 77° Fahr. ) in from three hours ( Ustilago longissima) to fifty or sixty 
{Tilletia caries). 

(/) The most important genus of the order is Ustilago, with 117 
species, of which the most common are U. carlo ( TT. segetum) on wheat, 
oats, barley, and many grasses; XT. 7ieglecta, on Seiaria glauca ; TT. 
maydis, on Indian corn. Tilletia contains 29 species, including T. 
caries (T tritici), and 1. lems on wheat; Sorosporium, 18 species, six 
in the United States; Urocystis, 24 species, including U. anemones on 
Rauuuculacese, and JJ. cepulm on onions. 



BA8IBI0MTCETE8. 323 

415a.— Degraded Aseomycetes. There are several groups 
of greatly reduced Aseomycetes which properly belong here 
( Gym noasci, Exoasci, and Saccharomycetes, p. 214). They are 
either parasitic (as in Exoascus), or saprophytic (as in 
Gymnoascus and Saccharoiuyces), and consist of single or 
few cells, ultimately producing ascospores. 

415b.— Imperfect Fungi. Here too must be placed for 
the present many " Imperfect Fungi/' of which only the 
conidial states are known. They constitute the groups 
Sphceropsidem, Melaiiconiece, and Hyphomycetem, and include 
about 8,500 species, many of which are parasitic upon higher 
plants. 

§ lA"". Class Basidiomycetes. 

416. — The plants of this class are among the largest and 
finest of the fungi. They are mostly saprophytes, provided 
with an abundant mycelium, which ramifies through the 
nourishing substratum, and from which there arises after- 
ward a spore-bearing growth, the sporocarp. The spores, ol 
which but one kind is yet certainly known,* are produced 
upon slender outgrowths from the ends of enlarged cellSp 
termed basidia. The basidia are usually so arranged as to 
form an hymenium, which is at length external in Hymeno- 
mycetes. and internal in most Gasteromycetes, 

417. — The sexual organs probably precede the formation 
of the sporocarp, but they have been but little studied. 
(Ersted discoveredf bodies in Agaricus variabilis which, 
judging from his description, bear a considerable resemblance 
to the sexual organs of Peziza. Whether they occur through- 
out the class is at present entirely unknown, and as (Er- 
sted's discovery has not been confirmed by other observers, 
the whole question as to the sexual organs of the Basidiomy- 

* (Ersted, in " Kongelige Danske Videnskabernes Selskabs Forliand- 
linger," Copenliagen, 1865 (translated in Qr. Jour. Mic. Science, 1868, p. 
18), describes certain little stalked bodies wliich lie found growinpf upon 
ihe mycelium of Agaricus variabilis, and wliich lie regards as conidial 
in their nature. Spermatia also occur on the Tremellini. 

I Described in Ins paper ju>t referred to above. 



324 BOTANY. 

cetos must be considered as involved in much doubt. Two 
orders may bo readily separated in this class, the Gasteromy- 
cetes and the Ilymenomycetes. 

418.— Order Gasteromycetes. The plants of this order 
arc saprophytes, })roducing sporocarjos which are ofcen oi 
large size, and usually of a more or less globular outline, 
sometimes long-stalked. The spores are always borne m the 
interior of more or less regular cavities, and from these they 
escape by the drying and rupture of the surrounding tissues. 

419. — The mycelium of the Gasteromycetes penetrates the 
substance of decaying wood, and the soil filled with decaying 
organic matter. It is composed of colorless jointed hypha3, 
which usually aggregate themselves into cylindrical root- 
like masses. After an extended vegetative period, the my- 
celium forms upon its root-like portions small rounded 
bodies, the young sporocarps, which increase rapidly in size, 
iind assume the form characteristic of the different genera. 

420o — The sporocarps are comj^osed of hyphae which are 
tnuch interlaced ; in the interior they are more loosely ar- 
ranged, while externally they form a more or less well-defined 
limitary tissue, the peridium. In some genera the peridium 
is composed of two or more layers, as in the Earth-star {Geas* 
ter). The spores are borne upon hymenial layers which line 
cavities in the interior of the sporocarp. The basidia upon 
which the spores are borne are the rounded or elongated ter- 
minal cells of hypha-branches ; each basidium bears four or 
more (frequently eight) spores uj)on the ends of as many 
small projections (spicules). In Phallus and its allies the 
hymenial cavity lies beneath the double peridium and paral- 
lel to its surface ; when the spores are formed, by the rapid 
growth of the axial portion of the sporocarjD, the hymenium 
is carried up through a rent in the apex of the peridium and 
the spores thus set free. In the Earth-star (Geaster), Puff- 
ball {Ly coper do7i), and their allies, the hymenial cavities are 
numerous, of irregular shape, and scattered through the tis- 
sue of the sporocarp. The spores are set free by the rupture 
of the peridium, and the drying of the whole sporocarp, 
thus reducing its interior hyphse to a fine powder. In the 

Puff-ball the single peridium ruptures irregularly, but in tht> 



GA8TER0MYGETE8. 325 

Earth-star the outer peridium, which is dense, and when dry 
quite hard, splits from the top into partially separated seg- 
ments, which recurve and expose the inner more delicate perid- 
ium ; the latter ruptures more or less regularly at the top, and 
thus allows the escape of the spores and dusty broken-up 
hyphse. 

421. — In the curious little Crucihulum and its allies the 
structure and mode of development are much more compli- 
cated. The mycelium, which grows over the surface of de- 
caying wood, forms first a rounded mass of hyphsB in its 
centre ; this becomes cylindrical, and then undergoes several 
remarkable changes. In the interwoven hyphge of the inte- 
rior, at certain points, there is a very great increase in the 
number of hyphae and the density of the tissue ; this takes 
place with such regularity that several round bodies are 
formed. The interior of each of these round bodies is at 
first composed of interwoven hyphse, but these become mu- 
cilaginous, and finally entirely dissolved, forming a central 
cavity in each mass ; into these cavities hypha-branches now 
grow, and line them with an hymenial layer of spore-bearing 
basidia. The round bodies are thus sporangia. While the 
above-described changes are going on, the tissue lying between 
the sporangia undergoes conversion into mucilage, and be- 
comes entirely dissolved, leaving only a surrounding wall 
(the peridium), and slender pedicels composed of hyphse, 
which support the sporangia. When these changes are com- 
pleted, the peridium ruptures at the top and opens out, 
forming a cup-shaped rci. eptacle, in which the sporangia lie. 
The sporocarp of Orucibulum is thus a much more highly 
developeu organism than that of Ly coper don, although not 
differing from it in any essential point of structure. 

422. — No sexual organs have yet been discovered in the 
Gasteromycetes, but analogy points to their probable exist- 
ence upon the mycelium just previous to the first appearance 
of the spore-bearing portion of the plant (sporocarp). 

423. — The mode of germination of the spores is as yet 
almost entirely unknown. 

{oC) The principal genera of tlie Gasteromycetes are Phallus, which in- 
cludes the common Stink-horn ; Lycoperdon including several species of 



3^6 



BOTANY. 



Puff-balls, of which the best known is L. giganteum, the Giant Puff- 
ball, an edible species, from ten to thirty cm. in diameter ; Oeaster, 
the Earth-stars, including several species, and Crucibuium, of which G. 

Dulgare is very common. 

(b) This order presents 
no unusual difficulties to 
the student, and it is one 
whicli should receive more 
attention than it has hith- 
erto. For the study of 
the structure the speci- 
mens should be taken in 
their earlier stages, as but 
little can be made out 
after the hyphae begin 
breaking up or dissolving. 

424. — Order Hy- 
menomycetes. These 
plants are doubtless to 
be regarded as the 
highest of the chlo- 
rophyll - free Carpo- 
sporeae. They are not 
only of considerable 
size (ranging from one 
to twenty centimetres, 
or more, in height), 
but they present a 
structural complexity 
which is so much 
greater than that of 

Fig. 225.— Development of Agaricus campesfris. the other Orders, that 
A, underground mycelium (m), bearing numerous , x i x i 

yonng sporocarps of various sizes. /., vertical sec- tllCy CaUUOt DUt DC rC- 
tion of a young sporocarp, showing its attachment -, t ,-, i • i ; 

to the mycelium, m. //., vertical section of an gardeO. aS the highest 
older sporocarp, showing the annular opening,^. p ii ^ -P,-,^^^ T ;u^ 

///., the ^ame at a sull later stage. IV., young sporo- ^I i^lie lUngl. IjlKe 
carp, with stalk (st) ; rudimentary gills (/), and the ii r!-ciofprnTnvppfp«5 

beginning of the veil («). F., sporocarp near v ma- ^^^^ vj-dy&LeiumjutJLeto, 
ture ; m, mycelium; A, pilens ; I, the gills (hyme- f]^py Drodnce an abun- 
niallamellEe); v, the veil, not yet ruptured; i, a very ^^^^J P^^^"-lce an auun 
young sporocarp. All natural size.— After Sachs. dant myCClium under- 
ground, or in the substance of decaying wood ; it fre- 
quently consists of multitudes of whitish jointed hyphae, 
which are loosely interwoven, but in some cases chey be- 




HYMEN0MYGETE8. 



327 



come densely felted into tough masses five to ten or more 
millimetres in thickness, and of many centimetres in 
breadth and length ; it frequently also becomes compacted 




Fig. 226. — A, cross-section of the gills or lamellae {I), of Agaricus campestris ; h, 
portion of pileus ; B, section of one of the gills, more highly magnified ; t, the cen- 
tral tissue of the gill {trama) ; sh, the sub-hymenial layer of short, rounded cells ; 
hy, hymenium. O, a small portion of £, more highly magnified (x 550) ; t, trama ; 
sh, sub-hymenial layer ; q, young basidia and paraphyses ; s\ basidium with spores 
in earliest stage; s'^ basidium with spores nearly ripe; s'^\ basidium with ripe 
spores ; s'^^', basidium from which the ripe spores have fallen. — After Sachs. 

into cylindrical root-like forms (Fig. 225, A, m). Upon the 
mycelium there arise, after a longer or shorter period of vege- 
tation, small rounded or oblong masses, the young sporo- 



328 BOTANY. 

carps. Tlicse are composed of parallel vertical hypliae, 
wliich grow upward, and finally bend out laterally, or send 
out lateral branches at the top, forming the umbrella-shaped 
pileus common in many of the genera (Fig. 225, V., h). 

425. — In the common Mushroom {Agaricus cam^jestris) 
the young sporocarp is at first composed of a mass of similar 
hyphse (Fig. 225, /.) ; somewhat later, however, an annular 
opening a little below the apex is visible in a longitudinal 
section (Fig. 225, //., /) ; this enlarges, and the overlying 
tissue becomes the pileus (Fig. 225, ///., IV., and F., h), 
while that between the opening and the margin of the sporo- 
carp becomes the *^^veil" (Fig. 225, IV. and F., v), which 
finally, by the rajoid expansion of the pileus, becomes rup- 
tured, leaving an annular fragment (the ring, or annulus) sur- 
rounding the stalk of the fully developed sporocarp. Upon 
the under surface of the pileus the hyphse form a great 
number of thin radiating plates or lamellae, the so-called 
gills, and upon their surfaces there develops an extended 
hymenial layer. The hymenium consists of elongated cells, 
which are slightly club-shaped, and placed closely side by 
side perpendicular to the gill surfaces (Fig 226, B and C). 
Some of these cells, the basidia, are somewhat longer than 
the rest, and have, in this species, two, and in most others, 
four, slender projections, upon which spores (basidiospores) 
are eventually produced (Fig. 226, Cy s', s", s'"). Here and 
there upon the hymenium there may be found larger bladder- 
shaped cells, looking like overgrown sterile basidia ; their 
significance is not known, and they have received the name 
of Cystidia (Fig. 226«). In some other genera the hyme- 
nium, instead of extending over lamellae, is found lining the 
walls of vertical pores, as in Polyporus, or covering depen- 
dent spines, as in Hydnum, or spread out oix the smooth, 
surface of the sporocarp, as in Stereum. 

426. — The development of the spores of the Hymeno- 
mycetes takes place, according to De Bary,* as follows : The 
young basidia, which have much the shape of the young asci 

* " Morpliologie und Pliysiologie der Pilze^ Flecliten, und Myxomy- 
cecen," 1865, p. Ill, et seq. 



IIYMEN0MTGETE8. 



329 



of the Ascomycetes (Fig. 19G, a, J), and c), are filled with 
granular protoplasm ; when the projections {sterigniata) 
make their appearance, the protoplasm in the basidium 
passes into them, and is slightly withdrawn from its lower 
end. Each sterigma swells at its extremity into a bladder- 
shaped body, the young spore, and as it enlarges the proto- 
plasm of the basidium is passed into it. By the time the 
spores are full grown the protoplasm has nearly all disap- 
peared from the basidia. The spores, when ripe, separate 
themselves from the sterigmata by 
a transverse partition, and soon 
fall off. 

427. — With regard to the ger- 
mination of the spores but little is 
known, but in Coprinns, according 
to Van Tieghem,* they give rise to 
a mycelium, and this is probably 
the case with all. 

428. — The existence of sexual 
organs in the Hymenomycetes is 
still involved in mncli doubt. Oer- 
sted described! long ago certain 
bodies which he discovered on the 
mycelium of Agariciis variabilis 
just before the formation of the 
sporocarp. They .are described as 
consisting of two kinds of cells, 
viz., (1) single curved, and almost reniform cells, which grow 
out from the sides of the hyphae ; they are .02 mm. long and 
about . 01 mm. in diameter, and appear to be separated from 
the hyphee from which they grow by a septum ; (2) very slen- 
der filiform cells, which grow out from beneath the former. 
OSrsted saw (in two instances) a union of these two organs. 
He came to the conclusion that the sporocarp was the result 
of a growth due to several such unions — i.e., that the sporo- 
carp was the result not of one, but of several fertilizations. 




Fig. 226a.— A. small portion of 
the hymenium of Gomphidiuw,. 
a, sterile cells ; b, basidia— each, 
with some of the spores attached; 
c, a cystidium.— After De Seynes. 



* ''Comptes rendus," 1875. 

f In the work already cited in tlie foot-note on p, 323. 



330 BOTANY. 

For some reason these observations have fallen ont of notice, 
and they still arc wanting confirmation. The close resem- 
blance of these organs, as described, to the sexual organs of 
Feziza, renders it probable that they are actually sexual in 
their nature. 

429. — More recently Reess has published the results of 
his observations upon Cojprinus stercorarms.^ He found 
that upon short lateral branches of the young mycelium 
many minute bodies (spermatia) are produced ; these, after 
falling off, come in contact with a thick three-celled body 
(carpogonium ? ), which they are supposed to fertilize. 
Afterward from the basal cell numerous filaments grow 
out, and eventually give rise to the sporocarp. f 

(a) In tlie study of the tissues of tlie Hymenomycetes young and 
perfectly fresh specimens are the best ; where this is impossible they 
may be preserved in alcohol, and then studied at leisure. Thin trans- 
verse sections of the gills will invariably show basidia and spores. 

{b) The genera of this order differ not only as to the disposition of 
the hymenium,but also as to the form of the sporocarp. With respect 
to the latter, it is symmetrical and stalked, as in the common Mush- 
room, or unsymmetrical and sessile, as in many species of Polyporus. 
The texture of the sporocarp also varies from soft and deliquescent to 
hard and durable, 

(c) The more common genera are Agaricus, with several hundred 
species, Boletus, Polyporus, Hydnum, Stereum, and Clavaria. 

(d) Nearly related to the Hymenomycetes, if not indeed to be included 
with them, are the Tkemellini, which are gelatinous fungi, upon whose 
uneven surfaces is spread an hymenial layer, composed of basidia re- 
sembling those of Hymenomycetes. Sachs regards these plants as con- 
stituting a group related to, but distinct from, Hymenomycetes. 

(e) Many species are edible and nutritious. Agaricus campestris, the 
Mushroom, is commonly cultivated. Dr. M. A. Curtis found in North 

* Dr. Max Reess," Zur Befruchtungsvorgang bei den Basidiomyceten," 
1875. Van Tieghem, in " Comptes rendus," 1875, p. 378, makes pub- 
lic the results of his investigations, which are essentially the same as 
those of Reess, but a few months later he withdraws his statements • 
" Comptes rendus," 1875, p. 877. 

f It is scarcely necessary to refer to the paper by W. G. Smith in 
" Grevillea," 1875, p. 53, in which he describes a fertilization of the 
spores by spermatozoids developed by the cystidia. The many other 
evident errors in the paper make the value of his observations upou 
the supposed organs of fertilization exceedingly doubtful 



CHAR AC E^. 



331 



Carolina thirty- eight edible species of Agaricus, eleven of Boletus, nine 
of Polt/porus, seven of Hydnum, and thirteen of Clavaria. 

(/) Polypori'es Bowmani of the Carboniferous is the oldest knowi? 
member of this order. In the Tertiary the modern genera Lenzites, 
Polyporus, and Hydnum are represented. 



V. Class OnARACEiE. 



430. — In tliis small group of chlorophyll-bearing aqnati-c 
plants the sexual organs, while still preserving essentially 
the structure common to other Oarposporeae, present con- 
siderable modifications. The female organ consists of a 
^'central cell" or carpogonium (Fig. 227, c), which is the 
terminal one of a row of cells {a, 
I, c, Fig. 227). From the basal 
cells there grow out five elongat- 
ed cells (d, d, Fig. 227), which 
take an upward direction and 
surround the carpogonium ; they 
cohere laterally, so as to form a 
complete coverino-. The top of 

, , . T . T XT 1 I'ig- 227.— Development of the 

this enveloping sheath becomes carpogonium of mteiia jiexms, 

shown in vertical section, partly dia- 
grammatic. A, very early stage ; 

c, the central ell supported upon 
the small nodal ceil, b, and the 
larger cell, a; d. d, rudimentary 
enveloping cells. B, the same some- 
what later— the enveloping cells, 

d, d. have almost completely en- 
closed the centra! cell, c ; i. i, cells 

. ^ ,-, . which form a crown upon the en- 

COmeS twisted, so that each en- veloplngcells. x 300.— After Sachs. 




modified into a projecting crown 
of five (or by division ten) more 
or less divergent cells {i, i, Fig. 
227 Bj and c, Fig. 228, A). 
Finally, the whole envelope be- 



veloping cell passes spirally around the carpogonium (A, 
Fig. 228). 

431. — The male organ, or antheridium, consists of a 
globular body composed externally of eight spherically tri- 
angular cells, called the shields, which are united by their 
zigzag margins (a, Fig. 228, A). From the centre of each 
shield there projects into the cavity of the antheridium a 
cyhndrical cell [manuhrium), and upon each of these there 
are borne large numbers (twenty to twenty-five) of long 
coiled and bent many-celled filaments {h and c, Fig. 229). 
Each filament contains from one to two hundred cells, 



'332 



BOTANY. 



whicli are at first filled with granular protoplasm ; after- 
ward each cell develops a single spirally coiled spermato- 
zoid. When the antheridium is mature — i.e., when the 
spermatozoids are fully formed — the shields separate from 
each other, and thus expose the filaments (Fig. 229). The 
spermatozoids escape by the rupture of the walls of the fila- 
ment cells ; each consists of a slender spiral thread of proto- 
plasm, thicker at one end than the otlier, and provided at 

the more attenuated ex- 
tremity with two very del- 
icate and greatly elongated 
cilia (Fig. 229, d). By 
means of these cilia the 
spermatozoids movf 
through the water with a 
spiral' rotary motion. 

432.— Fertilization takes 
place by the entrance of . 
spermatozoids through the 
orifice between the diverg- 
ing cells of the crown ; they 
come in contact with the 
apex of the carpogonium, 
'^ where the cell-wall is ap- 
parently absent ;" as a re- 
sult of this union, the 
enveloping cells become 
thicker walled, hard, and 
dark -colored, forming a 

of the intcrnone of the loaf ; 6r, cortical cells -\ j • x* j_- 

of the leaf A x about 33 ; B x 240.-After Qcnse and rcsistmg coatmg 
^^'^''- to the fully formed carpo- 

spore within. The seed-like sporocarp thus formed soon 
separates itself from the parent plant and falls to the bot- 
tom of the water, where it remains until the advent of favor- 
able conditions for germination. 

433.— In germination the sporocarp gives rise first to a 
simple structure consisting of a single row of cells (the pro- 
embryo), and from this the more complex sexual plant is 
developed by the growth of a lateral bud-cell. The sexual 




Fig. 228. — Reproductive organs of Ohara 
fragilis. A, a central portion of a leaf, b, 
with an antheridium. a, and a carpogonium, 
5, surrounded b.v th'- spirally twisted envelop- 
ing cells ; c, crown of five cells at apex; (3^ 
sterile lateral leaflet- ; Z?', large lateral leaf- 
let near the fruit ; (3'^ bracteoies spring ng 
from the basal node of the reproductive or- 
gans. B. a younsi; antheridium, a, and a 
young carpogonium, $k; w,^nodal cell of 
P af ; V, inieimediaie (ell betwi-en xv and the 
basal node ceil :f the antheridium ; I, caviiy 



CHARAGEJEJ. 



333 



plant is composed of a jointed stem, wliicli bears whorls of 
leaves at regular intervals. The stem is one-celled in trans- 
verse section, as in NitelJa, or it has a large axial cell, which 
is surrounded by many long narrow ones, which form a 
cortical envelope, as in many species of Cliara. In some 
species the stem and leaves become incrusted with lime, giv- 
ing to them a good deal of hardness and brittleness. 

{a) The class is readily divisible into two orders — Nitellese and 
Cliarese.* 

Order Nitellese. — In this order the stem and leaves are always 
naked — i.e., not cor- 
ticated ; the leaves 
are in whorls of 
five to eight, and 
bear large leaflets, 
which are often 
many - celled. The 
sporocarps arise sin- 
gly or in clusters in 
the forkings of the 
leaves, and each has 
a crown consisting 
of two superimposed 
whorls of five cells 
each. 

These delicate 
plants occur in 
ponds and streams, 
and are rarely more 
than a few centi- 
metres in height. 
Two genera — Nitella 
and Tolypella — are 
distinguiahed by the 
position of the antlie- 
ridium, which is terminal upon the single node of the primary leaf in 
the former, while in the latter it is lateral, and the primary leaf has 
two or three nodes. 

The species of Nitella (ten to fifteen of which are American) are ar- 

* What follows is mainly from a synopsis of the Characese, furnished 
for this work by Dr. T. F. Allen, the author of " Characese Americanae," 
now issuing in numbers. Use has also been made of Dr. B. D. Hal. 
sfed's paper on the " Cassification and Description of the Americaii[ 
species of CharaceaR," published in Proc. Boston Soc. Nat. Hist., 1879. 




Fig. 22^.— Cha7'afragilis. a, an isolated shield, m, seen 
from within, with manuorinm bearing the filaments, b, in 
which the spermatozoids are developed ; c, a small portion 
of one of the filaments, th-^ spermatozoids not shown ; d, 
two free spermatozoids. a and 6 X 50 ; c and d X 300.— 
After Thuret. 



334 BOTANY. 

ranged under three tribes ; our more common species on]y are given 
below. 

Tribe A, — Munartlirodactylm, with tlie terminal segments of the 
leaves one-celled. 

N. flexUis, N. traaslucens, N. gelatinosa. 

Tribe JS, — Diarthrodactylm, with the ultimate segments of the 
leaves two-celled. 

N. gracilis, N. tenuissima. 

Tribe C, — Polyarthrodactylce, with the ultimate segments of the 
leaves three to six-celled. 

N. capillata, iV". intricata. 

The genus Toly]iella contaius about fi dozen known species, most of 
which are American. 

Order Chareae. — In this order the stem and leaves are sometimes 
naked, and sometimes corticated ; the leaves are in whorls of six to 
twelve, and their bracts or leaflets are always one-celled. The sporo- 
carps arise upon tlie upper side of the leaves, and each has a crown of 
one whorl of five cells. 

Tliese plants resemble the Nitellese in size and habit. The species 
are separated into two genera, LycTinothamnus and Ghara. The former 
has no representatives in America; it may be distinguished by the an- 
theridia being by the side of the carpogonia instead of below them, as 
is the case in Chara. 

The species of Chara are arranged under three tribes ; there are 
about a dozen representatives in America, the more important of which 
are here given. 

Tribe A, — Astephance, with no circle of stipules. No American 
representative. 

Tribe S, — Haplostephance, with a circle of stipules consisting of a 
simple series of cells. 

Ch. coronata, Ch. Hydropitys. 

Tribe C — Diplostephance, with the stipular ring double. 

Ch.fcetida, Gk.fragilis, Ch. gymnopus. 

(&) The genus Ghara is a very old one ; some species occur in the Sec- 
ondary (Jurassic) strata, and in the Tertiary (of Europe) they are very 
abundant, no less than thirty-seven species being recorded by Schim- 
per.* According to Lesquereuxf no fossil species of Characeee have 
yet been discovered in America, which is a remarkable fact, for at 
the present time the plants of this group are as abundant here as in 
Europe, and the sporocarps possess great durability and a,re likely to 
be preserved as fossils. 

* " Traite de Paleontologie Vegetale," par W. Ph.' Schimper, Paris, 
1869-1874. 

I " Contributions to the Fossil Flora of the Western Territories; 
Part II., The Tertiary Flora," by Leo Lesquereux, Washington, 1878. 



GLA88IFICATI0N OF THALLOPHYTES. 



335 



Areangement of the Classes of the Cabpophyta. 



,?..?.....—> 



..?..? 



> 



V 



VI. The Olassificatiok of Thallofhttes. 



(1.) The classification of the Thallopliytes, outlined in tlie preceding 
pages, is essentially that given by Sachs in the fourth edition of his 
** Lehrbuch." Sachs, however, considered the Protophyta, Zygophyta, 
I Oophyta, and Garpophyta to be Classes, whereas in this book they are 
raised to Divisions, co-ordinate with Bryophyta, Pteridophyta, and Pha- 
nerogamia. It is evident, even from the hasty examination sketched in 
the preceding pages, that there are three well-marked kinds of repro- 
ductive apparatus in the Thallophytes, which are, to a considerable 
degree, distinct. There are, of course, here and there cases in which 
one kind merges into another, but this is no more than is to be observed 
in everything else throughout both the vegetable and animal king- 
doms. After making all due allowance for the doubtful cases, the fact 
yet remains that there are three kinds of reproductive apparatus in the 
Thallophytes, which are as readily distinguishable as are those of the 
Cormophyte Divisions, Bryophyta, Pteridophyta, and Phanerogamia. 

(2.) Of the differentiation of tissues we know less ; but enough is 
known to warrant the statement that, as in the Divisions of the Cormo- 
phytes, there is a progressive increase in complexity as we pass from 



336 BOTANY. 

tlie lower to tbe liiglier Tliallopliytes. Thus tlie Zygopliytes, as a rule, 
are single cells {DesmidiaceOB and IJiatomacem), or rows of cells {Zygne- 
macece, etc.), of simple structure; the Oophytes are generally single 
cells of a complex structure (OadoMastece), rows of differentiated cells 
{(Edog ordeal), or even tissues, forming structures which have, in some 
eases, a close approximation to stems and leaves (Fucacece) ; the Car- 
pophytes are all multicellular ; the lower ones are made up of rows of 
cells, which are generally united into a plant-body (sporocarp of Asco- 
mycetes and Basidiomycetes), while in the higher ones there are tissues 
which form stems and leaves (some Floridem and Charw em). 

(3.) It can scarcely be doubted, then, that the three Thallopliyte groups 
Zygophyta, Oophyta, and Carpophyta, are as much entitled to rank as 
Divisions as are those of the Cormophytes. The Protophyta constitute 
a provisional group, but while it is very likely that many of the forms 
now included in it maybe placed elsewhere when they are better un- 
derstood, it is extremely improbable that all will be thus disposed of ; 
it seems more probable that the group may be preserved, very likely in 
a modified form, as a sort of primary Division. 

(4.) The arrangement followed in this book may be made plainer by 
the subjoined table. The Classes only (printed in small capitals) 
are given, excepting where, for obvious reasons, it is necessary to 
particularize more closely (Orders and genera in lower case). The 
groups on the left are composed of chlorophyll-bearing plants, and 
are regarded as the proper representatives of the Divisions. The 
groups on the right hand (printed in italics) are composed of plants 
which are parasitic or saprophytic, and which, as a consequence, show 
more or less of degradation in their vegetative parts ; the absence of 
ciilorophyli here, as in the case of parasitic Phanerogams, is an accom- 
paniment of structural changes in the vegetative parts of the plant, 
which are always degradatioual in their nature. 



PROTOPHYTA. 

Myxomycetes. 



Cyanophyce^. 



SCHIZOMYCETES. 

SMcharomyeetes (?). 

ZYGOPHYTA. 



Pandorina, etc. 

Conjugate Mucorini. 



CLASSIFICATION OF THALLOPHYTES. 



337 



OOPHYTA. 



Volvox, etc. 
(Edogonie^. 



{ Feronosporei 



CCELOBLASTE^ 

FUCACE^. 

CARPOPHYTA, 

Coleocliaete. 
Floride^. 

ascomycetes. 

Uredinem (V). 
TTstilaginem (?), 

Basidiomycetes. 

Charace^. 

It will be instructive to compare tlie foregoing with other attempts, 
at an arrangement of the Thallophytes. 

(5.) The arrangement which has long been followed, and which is 
still in use in most English books, is that which divides the Thallo- 
phytes (considered a class) into three orders,* viz., 

1. Algce, aquatic and chlorophyll-bearing. 

2. Fungi, terrestrial, and destitute of chlorophyll. 

3. Lichenes, terrestrial, and containing green gonidia. 
Berkeley's arrangementf differs from this only in the relative rank of 

the groups. 

Alliance I. Al gales {Algce). 

Alliance TT Mvcetales j Fungales (i^^w^i). 
Alliance 11. Mycetaies -j Lichenales {Lichenes). 

Algae have usually been divided into three groups (sometimes called 
sub-orders), as follows : 

1. Chlorospermem, including all the chlorophyll -bearing plants of the 
Protophyta and Zygophyta, and all the Oophyta, excepting Fucacem. 

2. Bhodospermece, nearly equivalent to the Floridece. 

3. Melanospermem, including the Fucacece, Phmosporece, and some 
other plants. 

(6.) Fungi are still arranged in most English books in six groups 
(called orders, sub-orders, or even families), as follows ::{: 
1. Ascomycetes, nearly as in this book. 



* See Hooker's " Synopsis of the Classes, Sub-classes, Cohorts, and 
Orders," in the English edition of Le Maout and Decaisne's " General 
System of Botany," 1872, p. 1028. 

f " Introduction to Cryptogamic Botany," 1857. p. 81. 

X See Berkeley's" Introduction," already cited ; Berkeley's "Outlines 
of British Fungology," 1860; Cooke's "Hand-book of British Fungi," 
1871; Cooke and Berkeley's "Fungi, their Nature, Influence, and 
TJses," 1874; and Fries' " Systema Mycologicum," 1821. 



338 BOTANY. 

3. Physon.ycetes, including the Mucorini and Saprolegniacem. 

3. Jlyphomyceles, including Peronosporem, Penicillium, and many 
imperfect forms. 

4. Coniomycetes, including Uredinem and UHilagineos, and in addi- 
tion a great number of imperfect stages of Ascomycetes. 

5. Oasteromycetes, as in this book, witli the addition of Myxomy- 
cetes. 

6. Hymenomy cetes, as in this book, and including the Tremellini. 

De Bary* arranged Fungi under four groups, as follows : 

1. Phycomycetes. 

Saprolegni'icem. Peronosporece. Mucorini 

2. Hypodermise. 

Urediiieoi. UstdaginecB. 

3. Basidiomycetes, 

Tremellini. Hymenomy cetes. Oasteromycetes. 

4. Ascomycetes. 

Protomy cetes. Tuberacem. Onygenem. Pyrenomy cetes. Lis- 
cumy cetes. 
In both the foregoing arrangements of Fungi the Lichens are omitted, 
they being regarded as of a different nature. 

(7.) In 1872 Colin publishedf an outline of a classification of the Cryp- 
togams in which the old distinctions between Algse, Fungi, and Lich- 
ens were abandoned. He considered the Thallophytes as constituting 
a single class, co-ordinate with Bryophyta, Pteridophyta, and Phanero- 
gamia, and divided it into seven orders, and each of these into many 
families ; the latter are in most cases equivalent to what are called 
orders in this book. 

(8.) In 1873 Fischer proposed an arrangement X of the Thallophytes 
wliich in many respects is like that of Sachs. Like the latter, Fischer 
divided the Thallophyta (co-ordinate with Cormophyta) into four 
classes, composed in each case of chlorophyll-bearing and chlorophyll- 
free plants, the algSB and fungi. Instead, however, of considering the 
fungi as degraded forms, he regarded them as constituting a genetic 
line, distinct from but parallel to the algae. The Myxomycetes he 
placed in a third genetic line, near to but distinct from the fungi. 



*In Streinz: "Nomenclator Fungorum," 1861, p. 722, and also in 
"Morphologic und Physiologic der Pilze, etc.," 1865, preface, p. 6. 

f Ferdinand Cohn, " Conspectus familiarum cryptogamarum secun- 
dum methodum naturalum dispositarum," in " Hedwigia, " February, 
1872. 

X Given in Sachs' " Lehrbuch," fourth edition, p. 248. 



CLASSIFICATION OF THALLOPHYTES. 339 

(9.) The following- modification of the arrangement of the Thallo- 
phytes followed in this book would agree better with my present con- 
ception of this portion of the vegetable kingdom. It is clear that Ihe 
geueticliuesof descent (ascent) of higher plants have been only through 
the chlorophyll-bearing members of the Thallophytes. These, then, 
must constitute the great framework of the lower half of the vegetable 
kingdom, and the fact that many of their relatives have become de- 
graded by parasitism or saprophytism, and in many cases have multi- 
plied species enormously, must not cause us to lose sight of their true 
relation to one another. 

The Myxomycetes, no longer regarded as plants, are omitted. 
Probably the Volvociueae (including Pandoriua) should be excluded, 
also, as being more animal than plant in structure. 

Branch I. PROTOPHYTA. (Protophytes, Water- Slimes.) 

Single cells, or chains of cells, reproducing asexually (only?) by 
fission, and the formation of internal spores. 

Class 1. ScHizoPHYOE^. (Cyanophycese.) 
Order Chroococcacese, 

" Kostocacese, 
" Bacteriacece. 

Branch II. PHYCOPHYTA. (Phycophytes, Spore-Tangles.) 

Single cells, chains, plates, or masses (the latter sometimes forming a 
branching plant with rhizoids). Sexual reproduction by the 
union of two protoplasts to form a single resting-spore. 

Class 3. Chlorophyce^. 

Order Protococcoideae (including ArcMwycetes). 

"■ Conjugatese (including Mucoracece and Ento- 

mopMhoracece). 
" Siphonese (including Saprolegrdacece and Perono- 

sporacem). 
" Confervoideae. 
Class 3. Ph^ophyce^. 

Order Phseosporese. 
" Dictyotacese. 
" Fucoidese. 

Branch III. CARPOPHYTA. (Carpophytes, Fruit-Tangles.) 

Chains, plates, or masses (the latter often forming a branching plant 
with rhizoids). Sexual reproduction (where known) by the union 
of two protoplasts to form a spore fruit. 



340 BOTANY. 

Class 4. CoLEOCIIyETEJ5. 

Order C(^leocb£etaceae. 

Class 5. ASCOMYCKTES. 

Order PerispGriacem. 

^' Tuber acecB. 

" Pyrenomycetem. 

" Lichenes. 

" Discomycetem. 

*' VredinecB. 

" Usiilaginem. 

' ' Gymnoascem. 
" Imperfect FuDgi," doubtfully referred to this class. 
Order Splicer opsidecB. 

* ' Melanconiem. 

' ' HyphomycetecB. 

Class 6. Basidiomycetes. 

Order Oasteromyceteoe. 
' ' Hymenomyceiece. 

Class 7. Floride^. 

Order Gongylospermese. 
" Cocciospermese. 
" Nematospermeae. 
" HormospermesB. 
" Desmiospermeae. 
' * Corynospermese. 

Class 8. CHAROPHYCEiE, 

Order Characese. 



Literature. 



In the study of the fungi the following works will be found of 
great service : . 

A. De Bary: " Morphology and Biology of the Fungi, Mycetozoa, 
and Bacteria," 

P. A. Saccardo: " Sylloge Fungorum omnium hicusque cogni- 
torum." 

George Winter: "Die Pilze Deutschlands, Oesterreichs, und der 
Schweiz." 



CHAPTER XVIII, 

BRYOPHYTA. 

434. — This diyision includes plants of a much greater de- 
gree of complexity than any of the preceding. In all there 
is a well-marked alternation of sexual and asexual genera- 
tions. The first generation — that is, the one proceeding 
from the spore — bears the sexual organs, and hence it is 
called the sexual generation. After fertilization, and as a 
result of it, there grows a sporocarp, which consists of a case 
or body, in which spores arise asexually ; hence this is called 
the asexual generation. From these spores the sexual gen- 
eration is again produced. 

435. — The production of the sexual generation may take 
place either directly or indirectly. In the first a thallus-like 
structure is produced directly from the germination of the 
spore, as in some of the Liverworts (AntJwceros, Frullania, 
etc.) ; in most Mosses, however, there is first produced from 
the spore a Conferva-like mass of threads, the pro-embryo or 
protonema, and upon this buds arise, which grow into the 
leafy sexual generation. 

436. — The sexual organs of Bryophytes consist of arche- 
gonia and antheridia. The former are flask-shaped bodies, 
whose walls are composed of a single layer of cells. In the 
bottom of the cavity of each archegonium is a naked mass of 
protoplasm, the germ-cell, which is the essential part of the 
female organ. The antheridia are of various shapes ; but 
they are generally club-shaped, or somewhat spherical, stalked 
bodies, whose walls, like those of the archegonia, are com- 
posed of a single layer of cells. The antheridia are filled 
with, usually, a great number of sperm-cells, each of which 
contains a single spirally coiled spermatozoid. 



342 BOTANY, 

437. — Fertilization takes place by the spermatozoids find- 
ing tlieir way down the neck of the archegonium (open at 
this time) and uniting their substance with that of the germ- 
cell. The first result of fertilization is the formation of a 
wall upon the germ-cell, which then begins to divide into 
a mass of cells by the formation of diagonal partitions. 

438. — The sexual organs are generally numerous, and 
they are frequently produced in little clusters of several to- 
gether, surrounded by enveloping leaves (the j^erichcetium), 
thus forming a sort of flower. In some species the anther- 
idia and archegonia are in the same flowers {hermapJirodite), 
while in others they are upon different parts of the same jflant 
(monoecious), or upon entirely different plants {dioecious). 

439. — The second, or asexual, generation is always devel- 
oped from the fertilized germ-cell belonging to the first ; but 
w^hile it is nourished by the latter, there is no organic con- 
nection between the sexual and the asexual generations. 
The asexual generation consists of a spore-case, or s2)orogo- 
niitm, with a greater or less developed stalk, oi- seta, su2:>port- 
ing the former. The spore-case varies much in form and 
degree of complexity, being iu some cases but a globular 
body filled with spores, while in others its structure is quite 
complex, and difficult to understand. 

440. — The spores are produced from mother-cells, each of 
which gives rise by internal cell-division to four daughter- 
cells, the spores. The mature spores are provided with a 
double wall, the outer (exospore) being usually hard and 
somewhat roughened, while the inner {endospore) is thin and 
elastic. The interior of the spore is composed of colorless 
protoplasm, chlorophyll granules, starch, and minute drops 
of oil. In germination the endospore breaks through the 
exospore, and becomes prolonged as a narrow tube, which by 
division gives rise to the sexual stage of the plant. 

441. — In a portion of the Division the plant-body is either 
a true thallus, or a structure which is best described as 
thalloid in form ; in all of the Mosses, however, and some of 
the Liverworts, there is a differentiation into stem and leaf. 

442. — ISio true roots are found in the Bryophyta, but in 
place of them there are root-hairs, consisting of single cells, 



HEPATIC^, 343 

or rows of cells ; these are attached to the under surface of 
the thallus, or to the side of the stem, and serve to support 
and fix the plant, as well as to absorb nutritious substances 
for its sustenance. 

443. — The tissues of Bryophyta are much more highly 
developed than in the preceding divisions ; the epidermis is 
in many cases quite well defined, and here for the first time 
true stomata make their appearance (paragraph 119,page 91). 
The greater part of the 2)lant-body is in most cases composed 
of a well-developed parenchyma, composed of thin-walled 
cells, which are compacted into a true tissue. There is, 
moreover, a slight indication of the development of a fibro- 
vascular system in the elongated bundles of cells which oc- 
cur in the leaf veins and the axial portions of the stems of 
some of the species. The cells immediately beneath the epi- 
dermis are much thickened in some cases, so as to form a 
strengthening tissue. This may be regarded as a simple 
kind of sclerenchyma. 

444. — The Bryophytes are usually divided into two classes, 
the Liverworts [Hejoaticce) and the Mosses (Musci), 

§ I. Class Hepatic^. 

445. — In this class of plants, commonly called the Liver- 
worts, the plant-body is for the most part either a true 
thallus or a thalloid structure. Even when there is a differ- 
entiation into stem and leaves, it still retains some of the 
peculiarities of the thallus ; thus in most cases the |)lant- 
body has two distinct and well-marked surfaces, an upper or 
dorsal, and an under or ventral one, the latter bearing, for 
the most part, the rhizoids, by means of which the plant is 
fixed to the ground. Growth is always from an jipical cell. 

446. — The tissues of the Liverworts are quite simple, and 
even in the leaf-bearing kinds there is but little differentia- 
tion ; the leaves, when present, have no midrib or other veins, 
but consist of a simple plate of cells. The mode of branch- 
ing is dichotomous in the lower species — i.e., those with a 
thallus or thalloid plant-body — while in those which have 
stem and leaves it is lateral and monopodial. 



344 



BOTANY. 



447. — The leaves, when present, are usually in two rows 
(distichous), and are either opposite or alternate ; they are 
entire, serrate, or even lobed. There is frequently a third 
row of leaves (called amjphigastria) on the under side of the 
stem. 

448. — Most Liverworts are small in size, ranging from a 
few millimetres to several centimetres in length. They 
grow for the most part in moist places, upon the ground, or 
upon rocks, or the bark of trees. All are chlorophyll-bear- 




Fig. 2S0.— Mar chantia polymorpha. A, young thallus. B, an older thallns, with one 
gemma-cup ; v, v, emarginate apical region of the two young branches of the thallus. 
C, a two-lobed thallus, bearing gemma-cups. I), a portion of the upper surface of a 
thallus (magnified), showing the lozenge-shaped areolae, each with a central stoma, sp. 
I. to VI., development of the gemmae. /., very young ; //., the terminal ct-ll divided 
transv> rsely ; ///. , a later stage, with divisions in various directions ; IV., V, still 
later stages ; VI., outline of a fully developed gemma ; when it grows the new shoots 
will start out right and left from the two depressions on its sides.— After Sachs. 



ing plants, and they are usually of a green or brownish 
green color. 

449. — The asexual reproduction of Liverworts takes 
place by means of bodies of a peculiar kind, called gemmae, 
which are usually produced in special organs. This mode of 
reproduction is well illustrated in the genus Marchantia, in 
which small cup-shaped organs (4 to 6 mm. in diameter) de- 
velop upon the upper side of the thallus {B and 0, Fig. 
230). In each of these several hair-like papillae grow up, 



HEPATIC^. 



345 



and by the repeated division of tlieir apical cells produce 
upon each a little flattened mass of cells, the gemma. 




Fig. 231.— Male organs of Marchantia polymorpha. A, a portion of the thallus, t, 
■with two ascending branches bearing the antheridial receptacles, hu. B, vertical sec- 
tion through young antheridial receptacle, hu ; a, antheridium enclosed in a cavity 
which has a narrow opening, o; t, portion of thallus ; h, root-hairs ; b, leaf-like bod- 
ies seen in section. C, a nearly ripe antheridium ; st, its pedicel ; tv, the wall. J), 
two spermatozoids. Variously magnified. £> X 800.— After Sachs. 

gemmae, when full-grown, fall to the ground, and grow di- 
rectly into new plants. In some cases the gemmse are much 




Fig, 032.— Development of the antheridia of Riccia glauca. A, longitudinal section 
through the apex of the thallus ; s. apical cell of the thallus ; b, scale-like leaves, in 
section; a, a very young antheridium ; a', an older antheridium, surrounded by a 
growth of thallus tissue, w. B, a young antberidium, a, overarched by a growth oi 
the thallus. C, an older antheridium, in longitudinal section, x 500.— After Hof- 
meister. 

simpler than those just described ; in the Jungermanniaceae, 
for example, they consist of a few cells which are spontane- 
ously detached from the tissues in the margins of the leaves. 



34G 



BOTANY. 



450.— The sexual organs are situated in depressions in 
the upper side of the thallus, or upon the sides or ends of 
the stems, and are surrounded by peculiarly developed leaves 
{2)crichcdiu7}i) in the leaf-bearing forms. 

451._The antheridium is a more- or less globular— usually 
stalked— body, which arises from a single cell (hence mor- 
phologically a trichome) by the repeated subdivision of its 
terminal cells. Its outer wall consists of a single layer of 
cells {G, Fig. 231, tu), and its cavity is filled with a large 
number of sperm-cells, each of which contains a single 
spermatozoid. The sperm-cells escape by the breaking of 
the antheridium wall, and in the water in which this always 
takes place they rupture, and the spermatozoids are set free. 
Each spermatozoid is a spirally curved slender thread of 




Fig. 233. 



Fig. 234. 



Fig. 233.— Development of the antheridia of Marchantia iwlymorpha, in 'c section 
of a young antheridial disc, r, the growing anterior margin of the disc; from r to 
the left are shown the antheridia (a, a, «, a) in four stages of development; at sjj, sp, 
sp, are shown the stages of development of the stomata above the air cavities be- 
tween the antheridia. X 300.— After Hofmeistt r. 

Fig. 234. — A, longitudina-l section of the apex of the thallus of Riccia glauca. ar^ 
archegonium; c, germ-cell. B. the unripe sporogonium, sg, surrounded by the calyp- 
tra, which still bears the neck of the archegonium, ar. A X 560 ; £ X 300.— After 
Hofmeister. , . 



protoplasm, provided at the anterior end with two long 
ciha (D, Fig. 231). 

452. — In some cases the antheridia are developed singly 
upon the upper surface of the thallus, as in Biccia (Fig. 
232). In this particular case the antheridium is developed 
directly from an epidermal cell {A, Fig. 232, a), and so is 
^t first external ; it, however, soon becomes overarched 



HEPATIC^. 



347 



by the rapid growtli of the surrounding tissue of the thallus 
{A, B, and C, 
Fig. 232). In 
other cases the 
antheridia are de- 
veloped in great 
numbers upon 
special branches, 
as in Marchantia, 
A\^hich has a large 
" antheridial disc" 
{A and B, Fig. 
231, hu), in whose 
upper surface are 
to be found many 
imbedded anther- 
idia. That the an- 
theridia are actu- 
ally external in 
this case also, be- 
coming apparent- 
ly internal by the 
growing up of the 
surrounding tis- 
sues, is well shown 
in Fig. 233. In 
still other cases 
{e.g., in Junger- 
manniacecB) the 
antheridia are in 
the axils of the 
leaves, and occur 




Fig. 235.— The archegonia, and origin of the sporogo- 
nium otMarchantia polipnor ]}ha. I. and //., yonng arche- 
gonia ; e, germ cell ; si, lowest cell of axial row of cells. 
III. and /F., the same after the formation of a central 
canal by the absorption of the axial row of cells in the 
neck. F., the same when mature and ready for fertiliza- 
tion. VI., the base of a fertilized archegonium, the 

aino-lTTrkrin rrrnnna germ-cell, f, divided into two cells by a diagonal partition. 

Mii^ij/ ui 111 giuupb. YII, later stage of the same, showing further division of 

/IKO TliP i\v t^6 germ-cell, /. and the beginning of the growth of a 

^oo. xiic cti- perianth, pp. VIII, still later stage of the same, the 
perianth, pp, now enclosing the archegonium ; x, the 
witliered neck of the arcliegonium. IX., the unripe sporo- 
gonium, enclosed in the old walls of the archegonium, 
now called the calyptra, a ; f, wall of sporogonium ; 
st, the short, undeveloped stalk of the sporogonium. 
Inside of the sporogonium are the young elaters arranged 
radially, and between them are the spores. /. to VIII. 

Avhicll, by subdi- X 300 ;/X. about 30.-Al.er Sachs. 

vision in var'ous directions, gives rise to a more or less 



chegonium first 
appears as a simple 
papilla, composed 
of a single cell, 



34:8 



BOTANT, 



flask-shaped body ; this in its first state is composed of a 
layer of cells surrounding and enclosing an axial row of 
cells, but by the change of most of the latter into mucilage, 
and their consequent solution, the structure becomes tubular 
above. The lower cell of the axial row is the germ-cell {A, 
Fig. 234 ; e, and e, e, e, Fig. 235) ; it is a rounded naked 
mass of granular protoplasm. In Anthoceros the archego- 
nium is very simple ; a row of cells perpendicular to the 

surface of the 
thallus becomes 
filled with proto- 
|)lasm ; the low- 
er develops into 
a germ- cell, and 
the others dis- 
solve, forming 
thus a tubular 
opening to the 
germ-cell. 

454. — After 
fertilization the 
germ-cell divides 
successively in 
several direc- 
tions, giving rise 
to a tissue, which 
undergoes differ- 

P\g.2^Q.—Anthocerosla'ms. so-, the yonn? sporogonium ent moclltica- 

fiit vertically ; Z, the invuJucre, wliich is a portion of the -j-ip,YiQ iy, \\.p. A\^ 

thailus developed so as to form a kind of sheath; c, c, the ^^^^^^^ m Llie Uli- 

columella ; s, the spores. X 150.— After Hofmeister. fercnt OrdcrS but 

which becomes in every case a sporogonium (called in descrip- 
tive works a capsule) of some kind. In Riccia it is a simple 
globular case filled with spores {B, Fig. 234, sg) ; in AntJioce- 
ros it is an elongated body, with a single circular layer of 
spores (Fig. 236), while in other cases its structure is quite 
complex. In Marcliantia, the sporogonium, when mature, is 
a short-stalked, rounded body, filled with spores and radially 
placed thin-walled cells, the elaters, each of which contains 
one or more spiral fibres {IX., Fig. 235, and Fig. 240) ; it is 




HEPATIC^. 



349 



here surrounded by a periautli, a loose bag-like slieatli, which 
grows up from below the base of the young sporogonium, at 
length completely enclosing it ( F//. and F///.,rig. 235, pp). 
455. — The archegonia of the Liverworts occur singly, as 
in Eiccia, AntJioceros, etc., or grouped together, as in Mar- 
chantia, J linger mannia, and their allies. In Marchantia 
they grow in several clusters of four to six upon the under 
surface of the spreading top (the fertile receptacle) of a 
special branch of the thallus (Fig. 237). In many cases the 




Fig. 237. 



Fig. 238. 



Fig. 237.— Fertile receptacle of Marchantia polymorpha^ seen from below. 3t, its 
stalk, curiously grooved ; S7\ one of the rays of the star-shaped receptacle ; /, one of 
the sporogonia ; pc, pc, perichsetia, which surround several sporogonia. X 6.— After 
Sachs. 

Fig. 238.— Plant of Plagioehila asplodoides, with the bilateral leafy axis below, p, 
the perianth through whose top the sporogonium or capsule has pushed; a, an un- 
ripe sporogonium ; &, a ripe sporogonium split open to permit the escape of the spores. 
— After Prantl. 

sporogonium is, even when fully mature, sessile, or nearly so, 
there being but a very short stalk developed ; but in the 
Jungermanniacece, when the sporogonium is ripening, the 
tissue at its base increases rapidly, and gives rise to a long 
slender stalk, which pushes the spore-case through the dried- 
up wall of the old archegonium, and raises it to the height 
often of several centimetres (Fig. 238). 

456. — There are^various ways in which the spores are set 
ree from the ripe sporogonium or capsule. In Riccia it 



350 



BOTANY. 




Fig. 239.— Plant of An- 
thoceros hems. £', on the 
riglit, sporogonia un- 
opened ; IC, on the left, 
t^porogonia opened.— After 
Pninll. 



takes place simply by the decay of the sporogonium ; in 
Anthoceros the long sporogonium splits 
vertically into two long valves (Fig. 
239), while in the greater part of the 
class it splits regularly 
into a definite number 
(four to six) of recurv- 
ing segments ; in the 
latter the elaters, which 
are present, doubtless 
aid in setting the 
spores free. The struc- 
ture and development of the elaters are 
shown in Fig. 240. 

The following are tlie principal orders of the 
Hepaticse : 

Order Ricciacese. — Consisting of terrestrial or 
aquatic annual plants of small size ; the plant- 
body is a dicliotomously branched thalloid stem, 
■which bears a row of scale-like leaves upon the 
under side. The sexual organs occur singly on the 
upper side of the stem, and the sessile, spherical 
sporogonia (capsules) are immersed in it or sessile 
upon it ; the capsule breaks irregularly upon the 
decay of its walls ; and there are neither perianth 
nor elaters. 

Order AnthoceroteaB. — Terrestrial annual 
plants with an irregularly branched thallus. The 
sexual organs are imbedded in the upper surface 
of the frond, and are of very simple structure ; the 
sporogonia are long and narrow, and dehisce by 
splitting into two valves ; perianth none ; and the 
elaters, when present, imperfect and rudimentary. 

Order MarchantiaceaQ. — Terrestrial perennial 
plants, with a thick, creeping, and dicliotomously 
branched stem, furnished beneath with numerous 
scale-like leaves and root-hairs ; above, the stem is 
provided with a well-developed epidermis, and pe- 
culiar stomata of a complex structure, communi- 
cating with lozenge-shaped cavities (Figs. 78 and 
79, pp. 91-2). The sexual organs are developed on 
special erect branches, and they may occur on the 
same, or on distinct plants ; the sterile or antheridial branches, which 




Fig. 240.— Two ela- 
ters in different stages 
of development. The 
one on the left is seen 
to bean elongated cell 
with no trace as yet 
of the spiral thicken- 
ing of its wall. By its 
side are several young 
spores. The elater on 
the right is mature. It 
is composed of the spi- 
rally thickened por- 
tions of the wall, the 
intervening portions 
having broken away. 
A, A, are mature 
spores magnined. — 
From Le Maout and 
Decaisne. 



MU8CI. 351 

are sometimes very sliort, bear flattened discs in whicli the antheridia 
are immersed ; tlie fertile or arcliegonial brandies bear spreading 
discs, upon the under side of which the dependent archegonia are clus- 
tered. The ripe sporogonium (capsule) is enclosed in a perianth ; it 
opens by splitting- part way down from the top into several segments, 
and contains two-fibred elaters mixed with the spores. 

Marchantia polymorpha, a common species, is used by quacks as a 
medicine. 

Marchantia occurs in the Tertiary (Eocene) of Europe, but has not 
been detected in North America. 

Order Jungermanniacese. — Plants composed of a thallus, a thalloid 
stem, or a stem with two or three rows of leaves ; when there are three 
rows the third row is on the under side (constituting the ampliigastria). 
The sexual organs are distributed monoeciously or dioeciously ; in the 
thalloid species they occur much as in the MarcJiantidcem ; in the 
foliose forms the antheridia "are usually in the axils of the leaves, 
either singly or in groups," and the archegonia are most frequently 
clustered upon the summits of the shoots, and are generally concealed 
by the leaves. The ripe sporogonium (capsule), which is usually long 
stalked, opens by splitting into four parts from the apex to the base ; 
it contains one- or two-fibred elaters mixed with the spores. Many 
species are common on rocks and the bark of trees. 

The modern genera Jumjermannia, Frullania, and Lfjeunia were 
represented in the Tertiary (Miocene). 

g II. Class Musci. 

457. — The adult plant-body in this class, which includes, 
besides the Sphagnums, all the true Mosses, is always a leafy 
stem, which is rarely bilateral. It is fixed to the soil or other 
substratum by means of articulated root-hairs, or rhizoids, 
which grow out from the sides of the stem. The leaves are 
sessile, usually comj)osed of a single layer of cells, and either 
nerveless, or traversed longitudinally by a single rib, rarely 
by two ; they are arranged in two or three straight or spiral 
rows, and are usually inserted more or less obliquely to the 
stem. 

458. — The tissues of the Mosses present a considerable 
advance upon those of the Liverworts." In the stem there is 
usually a considerable thickening of the outer layer, or layers, 
of cells, constituting a kind of imperfect sclerenchyma. In 
some cases {Leucohryum, Barhula, etc.) the remainder of 
the stem is composed of thin-walled tissue (parenchyma), 



852 BOTANY. 

but in otliers {Funaria, Mnium, Bryum, etc.) tliere is an 
axial bundle of very narrow tb in-walled-cells ; in still others 
{AtricUum, Polytriclium, etc.) the cells of the central bundle 
are considerably thickened, and in the last-named genus 
there are extra-axial bundles. In a few cases tliere have 
been observed bundles of thin-walled cells extending from 
the leaves obliquely through the tissues of the stem to the 
central bundle. From the foregoing statements it cannot 
be doubted that the Mosses possess rudimentary fibro-vascu- 
lar bundles. Stomata resembling those of the higher plants 
occur on the capsules ; they are not found upon the leaves 
or stems. The stem always grows from an apical cell. 

459. — Mosses are, for the most part, aerial plants, growing 
uj^on moist earth or rocks, or even upon the sides of trees, 
a comparatively small number of sjDecies being aquatic ; they 
range in size from less than a millimetre to many centimetres 
in length, the most common height being from two to four 
centimetres. They are all chlorophyll-bearing plants, and are 
generally of a bright green color ; occasionally, however, they 
are whitish or brow^nish. 

460. — The sexual organs of Mosses consist of antheridia 
and archegonia ; they are usually found upon the end of the 
leafy axis, and generally occur in considerable numbers. 
Most of the species are either monoecious or dioecious, while 
some are hermaphrodite. There is, however, but little value 
to be attached to tlie kind of inflorescence, as it is often dif- 
ferent in genera which are certainly near allies. Even in 
the same genus some of the species may be dioecious, while 
others are monoecious or hermajDhrodite ; and occasionally, as 
in the genus Bryum, the three kinds of inflorescence are 
found ; rarely a sjDecies is itself variable in this respect — 
e.g., Bryum crudum, which is mostly hermaphrodite, but 
sometimes dioecious. 

461. — The antheridia are generally club-shaped, stalked 
bodies (spherical in Spliagnacece), with a wall composed of a 
single layer of cells enclosing a mass of sperm-cells, each of 
which contains a bi-ciliate, spirally coiled, thread-shaped sper- 
matozoid (Fig. 242,- B). When the antheridium is mature its 
wall ruj^tures when wet, and the sperm-cells escape iu a mass 



MUSCI. 



353 



of mucilage ; the walls of tlie sperm-cells break, and tlie 
spermatozoids are set free (Fig. 242). The antheridia are 
frequently intermingled with variously shaped hairs (jgara- 
fliyses), and about the cluster there may be one or more 




^« 







Fig. 241. 



Fig. 242. 



Fig. 241.— Female repiodnctive organs of a moss, Funaria Iiygrometrica. A, apex 
of the stem ; a, archegonia ; 6, leaves. B, archegonium ; b, base ; h, neck ; m, 
mouth. C, mouth of fertilized archegonium. A x 100, B x 550.— After Sachs. 

Fig. 242.— Male reproductive organs of the same moss. J, antheridium open and 
permitting the spermatozoids a to escape. B, b, sperm-cell of another moss {Poly- 
^nc^MTTi), with contained spermalozoid; c, spermatozoid free, with two cells at the 
pointed extremity. A x 350, B x 800.— After Sachs. 

whorls of leaves or bracts, giving to the whole much of the 
appearance of a flower of the Phanerogams. 

462. — The archegonia are elongated flask-shaped bodies, 
with a swelling base, and a long, slender neck (Fig. 241, 
B). The wall is composed of a single layer of cells^ except 



354 



BOTANY. 



below, where there are two layers. The neck of the arche- 
gonium at first contains an axial row of cells, but these 

into a 
just before 



become dissolved and transformed 

h 




Fi^. 243.— Development of the siTorogonium 
of Fimaria hygrometrica. A, longitudinal gec- 
tion of tlie archegonium, 5, 6, shortly after fer- 
tilization ; h, neck ; /, apical portion of young 
sporogonium ; f, basal portion of young sporo- 
gonium. B, vertical section of a femalelflower ; 
t\ young sporogonium elongating, and carrying 
up the remains of the old archegonium, c (ncjw 
called the calyptra) ; A, neck of old archego- 
nium. C, a later stage of the same. In B and 
C the sporogonia are seen to be growing down- 
ward into the tissues of the leafy stem A X 
500; 5 and C much less.— After Sachs. 



mucilaginous mass 
the time of 
fertilization. The germ- 
cell lies in the lower 
swollen portion of the ar- 
chegonium ; it consists of 
a naked rounded mass of 
protoplasm. At the time 
of fertilization the upper- 
most cells of the neck of 
the archegonium diverge 
from one another, and 
thus form an open chan- 
nel to the germ-cell. 

463.— Fertilization 
takes place in the water, 
or in the presence of a 
considerable amount of 
moisture. The spermato- 
zoids, which are j)roduced 
in great i^umbers, move 
through the water by 
means of their vibratile 
cilia, and some of them 
find their way down the 
channels of the archego- 
nia, where they unite their 
substance with the germ- 
cells. As a result of this 
union, the germ-cell sur- 
rounds itself with a wall 
of cellulose, and soon un- 
dergoes division in various 



directions, giving rise to a 
many-celled mass, the young sporogonium (/, /', Fig. 243, 
A). In most Mosses the young sporogonium elongates rap- 
idly, and while its upper end carries up the remains oi 



MU8CI. 



355 



the old arcliegonium {li_, Fig. 243, B and C), tlie lower end 
penetrates into the tissues of the leafy axis ; the upper end 
develops into a spore-case, while the remainder becomes a 
filiform stalk (seta) of greater 
or less length. In the Si^liag- 
nacecB, however, the sporogo- 
nium does not greatly elongate, 
but, on the contrary, remains 
quite short, while the end of 
the leafy axis, soon after the fer- 
tilization of the arcliegonium, 
elongates into a slender leafless 
stalk (pseudopodium), which 
carries up the developing sporo- 
gonium upon its upper expand- 
ed end (v, ps, Fig. 244, B and 
C). Essentially the same 
structure is found in A?idr(B- 
acecB and Pliascacem. 

464. — The ripe sporogo- 
nium (capsule, theca, or sjDore- 
case) is of various shapes, but 
generally more or less cylindri- 
cal or globose ; it differs much 
in its particular structure in 

the different orders, but in all Fig. 244.— Development of the eporo- 

111 gonium of Sphagnum acuUf'olivm. A, 

certain internal cells become longitudlDal section of a female flower; 

,-, n 1.1 -,. ar, aichegonia ; cA, young perichajtial 

spore mother-cells, which dl- leaveg ; y, upper leaves of the shoot 

vide into four daughter-cells, Sin^t'l r^rg^'^ofogSST" 
the spores. The capsule, when frevIgin.^llrc"cll;Xa^«n 
ripe, opens by the falling off of '^ ^^'i^^TliJ^ Xp'-t^'X 

a terminal lid (operculum) sporogonmm. in Ihe centre of the spo- 

T7-> \ rogonium is the columella and tne 

[SpliaqnaceCB and Bryacece), or ciirved row of spore mother-cells. c, 

. -^ p , T J , • Sphagnum squarrosum. so, ripe sporo- 

m a lew cases by splitting Ver- goninm ; a, operculum ; c, torn calyp- 

,•11 / A 1 \ • , 1 tra ; gs,t\\e elongated pseudopodiuni : 

tlCally [AjiarceaceCB] ; lll the cA, perlchiEtial leaves. All magnified.— 

small order Phascacem the cap- ^^er scWmper. 
sule is indehiscent, and the spores are set free only by its 
decay or irregular rupture. The ripe spores are roundish 
or more or less angled, and have a roughened or granulated 




356 



BOTANY. 



cxospore, which is generally yellow in color. Internally 
the spores contain, in addition to the protoplasm, oil-drops 
and chlorophyll granules. 

465. — In the germination of the spores, the exospore is 
ruptured, and the endospore protrudes as a tubular filament, 
which elongates by the continued growth of an apical cell ; 
partitions form at close intervals, and the threads branch 
freely, giving rise to a green Conferva-like mass, the pro- 
tonema (Fig. 245, B). In the SpJiagnacece, however, the 
protonema is a flattened mass, somewhat like the plant-body 




Fi^. 245.— Development of Funariahygrometrica. A, germinating spores ; «, rup- 
turi'd exospore ; w, w, young root hairs— on the opposite side of the spore is the 
beginnina; of the protonema ; ^\ vacuole in a germinating spore. B, part of a proto- 
nema three weeks after germination ; /i, a primary shoot with brown walls— from it 
arise several lateral branches b. K, a young bud or rudiment of a leaf-bearing 
axis ; w, a small root hair. .1 x 550 ; .5 X 70.— After Sachs. 

of the lower Liverworts. After a greater or less period of 
vegetation, there arise upon the protonema small buds, which 
develop into leaf -bearing axes (Fig. 245, B, X). These buds 
originate from single cells, which repeatedly divide them- 
selves by diagonal partitions ; the apical cell thus formed 
in each case becomes the apical cell of the bud, and the 
new axis. The leafy axes thus formed sooner or later bear 
the sexual organs, thus completing the round of life. 

466. — Mosses reproduce themselves asexually, sometimes 
in a manner quite similar to that of the Liverworts — e.g., in 



SPHAaNAGE^. 357 

Tetrapliis ijellucida, where the leafy axis frequently bears 
a terminal cup-shaped receptacle, containing many lenti- 
form stalked gemmae ; tliese separate spontaneously, and 
give rise to a kind of 23i'otonema, and upon this buds after- 
ward arise, from which leafy axes are developed. Many 
Mosses reproduce themselves by the formation of a pro- 
tonema from the leaves and the root-hairs, and from buds 
formed upon such a protonema new plants may arise. Even 
the protonema is capable of an asexual reproduction of itself ; 
sometimes its individual cells become rounded, spontane- 
ously separate themselves, become thicker walled, and then 
remain inactive for a time ; they thus remind one of the 
conidia of some Thallophytes. 

There are four well-marked orders of Mosses, as follows : 

Order Sphagnacese. — The plants of this order are large, soft, and 
usually pale colored ; they inhabit bogs and swampy places, and are 
known as the Peat Mosses. The protonema is a flat thallus, or com- 
posed of branched filaments, accordingly as it has developed upon a 
solid substratum or in water ; the leafy axis is usually much elongated, 
and as it dies away below it grows at the summit ; the leaves are usu- 
ally five-ranked, and are composed of two kinds of tissue, viz., (1) one 
made up of small chlorophyll-bearing cells, and (2) one made up of 
large perforated cells ; the latter are usually filled with water, and to 
them is due the well-known power possessed by the Peat Moss s, of 
retaining moii^ture for a great length of time. Root-hairs (rhizoids) are 
present only in young plants, their place being taken by the reflexed 
branches, which are always abundant. 

The inflorescence is monoecious or dicecious ; the rounded (almost 
spherical) antheridia occur singly by the sides of the leaves of catkin- 
like branches (not axillary, as stated in some books) ; the archegonia 
are developed upon the ends of certain branches {A, Fig. 244). The 
ripe sporogonium (capsule or spore-case) is globose, or nearly so ; its seta 
is short, but it is borne upon a more or less elongated pseudopodiuui, 
which resembles a seta. The old archegonium (calyptra) is ruptured 
irregularly by the growing sporogonium, and forms only a very imper- 
fect cap to the spore-case. In the development of the spores the cells of 
a layer parallel to the surface of the upper half of the capsule become 
modified as spore mother-cells [B, Fig. 244). At maturity a circular 
portion of the apex of the capsule spontaneously separates as a lid 
(operculum), and allows the spores to escape {C, Fig. 244, d). 

The order contains but a single genus, Spliagnum, represented in 
the United States by twenty-seven species. These are of some eco- 
nomic account, as they furnish u most excellent material for "pack- 
ing" in the transportation of living plants. 



358 



BOTANY. 



The genus Sphagnum was represented in the Tertiary (Miocene) of 
Euif)pe. 

Order Andrseaceee. — In this small order the little plants of which, 
it is composed have a short-stalked sporogonium, raised upon a pseudo- 
podium, as in the Sphagnaceca ; the sporogonium contains a layer of 
spore-forming tissue, disposed as in the preceding order ; but the ripe 
capsule opens by splitting into four longitudinal valves, in this remind- 
ing one of the Jungermanniacem. In the growth of the sporogonium 
the old archegonium is torn away at its base, and carried up as a cap 

(calyptra), which covers the apex of 
the capsule. 

The principal genus is Andrcea, 
represented in the United States by 
a few alpine or sub-alpine species of 
brownish or blackish rock -loving 
Mosses. 

Order Phascaceae. — These small 
Mosses are peculiar in having but 
a little development of leafy axis, and 
in their persistent protonema. The 
sporogonium is short-stalked, or ses- 
sile, and the pseudopodium is very 
short, or entirely wanting. The 
spores are, in the simplest genus {Ar- 
chidium), developed from a single 
mother-cell, while in the higher ones 
they develop from a layer of mother- 
cells, much as in the next order. 
The capsule is indehiscent, and the 
spores are set free only by its decay. 
roofonuim, /■; c, the calyptra; s, seta. The old archegonium persists as a 
C\ lougitudinal section of a capsule ; p„i.,^trn rnvprino- tliP r-nnmilp 
c, c, columella; d, operculum or lid, calyptra covering tne capsule, 
which will separate from the remainder The principal genera are ArcMdi- 
of the capsule at a : p, peristome ; s, y,, i r> i • mi 

spore-bearing layer ; A, air cavity sur- um, Plmscum, and Brucllia. The 
rounding the columella, and crossed by species are terrestrial, and many are 
confervoid filaments ; t, inferior con- .. 

n.'Ction of the columella with the tissues annuals. 

of the capsule. ^ and ^ slightly mag- i^ the Tertiary (Miocene) of Eu- 
nified ; V about 40 diameters.— After „ ., . „ -r., 

Sachs. rope a fossil species of Phascum has 

been found. 

Order Bryaceae. — The plants of this order constitute the true 
Mosses. They are usually bright green (in a few genera brownish), 
and in the great majority of instances live upon moist ground and 
rocks, or upon the bark of trees ; in a comparatively small number 
of cases the species live in the water. 

In the development of their tissues and the complex structure of 
their sporogonia the Bryaceae clearly stand at the head of the Bryo- 
phyte Division. The tissues, as indicated above (paragraph 458), attain 




Fig. 2A<o.—Funaria hygrometrica. A. 
a young leafy plant, g, with sporogo 
ninm st 11 covered -with the calyptra, c, 
£, leafy plant, (7, with nearly ripe spo 



BRYAVJS^. 



359 




Fig. 247.— Two cappules 
of Bryum argenteum. The 
one on the left is still per- 
fect ; at its apex is shown 
the lid or opercuhim ; the 
one on the right has dropped 
its operculum, exposing the 
peristome of long fringe- 
like teeth. Magnified. 



in some cases a development wliicli foreshadows tlie differentiation of 
the stem into the epidermal, fibro-vascular, and fundamental systems of 
tlie hig-lier plants. In Poly trie] mm, for example, there can be no doubt 
that the axial and extra-axial bundles of elongated cells with thickened 
walls found in the stem represent the fibro-vascular bundles of the 
Pteridophytes and Phanerogams ; the bundles 
of elongated thin-walled cells which pass 
downward through the stem from the base of 
the leaf, in Splaclinum, must also be regarded 
as representing rudimentary foliar bundles. 

While these higher Mosses cannot properly 
be classed with vascular plants, their tissues 
in some cases reach so high a development as 
to show that there is no abrupt change in pass- 
ing from the so-called non-vascular plants to 
the vascular ones. 

The inflorescence of Bryacege is hermaphro- 
dite, monoecious, or dioecious. The sexual or- 
gans are situated on the apex of the main 
stem (Acrocarpse), or of short lateral branches 
(Pleurocarpae). The sporogonium, in its de- 
velopment, carries up the old arche^onium as 
a calyptra, which quickly falls away in some genera {e.g., Bryum, 
Bartramia, etc.), while in others {e.g., Polytrichum, Pogonatum, etc.) it 
persists as a closely fittin<< covering of the capsule ; between these 
two extremes there are all gradations. 

The sporogonium is usually long stalked (Fig. 
346, B). The capsule is generally more or less 
ovoid or cylindrical. It is at first composed of pa- 
renchymatous tissue, which entirely fills up its 
interior; as it enlarges, however, an annular in- 
tercellular air cavity forms, separating a cylin- 
drical axial portion from the outer portion, which 
forms the wall of the capsule. The axial cylin- 
der remains in connection with the remainder 
of the capsule at its top and bottom {t. Fig. 246, 
(J), and it is, moreover, slightly connected with 
the capsule walls by chlorophyll-bearing confer- 
void filaments, which pass across the air cavity. 
The rather dense tissues below and surrounding 
the air cavity in the immature capsule are com- 
posed of chlorophyll-bearing cells, and the epidermis covering these 
portions is supplied with stomata. The spores are developed from a 
layer of cells (the third or fourth from the outside) in the axial cylinder 
(s, Fig. 246, G) ; and each cell of the spore-bearing layer produces four 
spores. The portion of the axial cylinder within the spore-bearing 




Fig. 248.— A pic a 
part of the capsule of 
Fontinalis untipyre- 
tica^ showing the 
double peristome. The 
outer row is made up 
of teeth, the inner of 
cilia. Magnified. 



3G0 BOTANY. 

layer is called the columella (c, c' , Fig. 246, C), wliile the two or tliree 
layers of cells exterior to it constitute the spore-sac. 

In all the members of this order, the capsule, when ripe, opens by the 
fallin<r away of a lid {operculum), which is composed for the most part 
of the epidermis covering the apical portion (Fig. 247). In moot of the 
genera, when the operculum falls off, one or two rows of teeth (the 
peristome) are exposed, surrounding the opening- of the capsule (Fig-. 
248). These teeth, which are always some multiple of four (4, 8, IG, 
32, or G4), are in most cases formed resi)ectively of the thickened outer 
and inner walls of rows of cells which lie beneath and parallel to the 
wall of the operculum, and converge toward its centre. Each tooth 
is thus made up of parts of several cells, and the transverse lines seen 
upon it are the thickened transverse walls which formerly separated 
the original cell cavities. 

The peristome of Polytrichum and its allies is composed of bundles 
of thickened cells, hence they are much firmer than in those genera in 
which they are made of fragments of cell membranes. 

The Bryacese include many genera, which are widely distributed 
throughout the world. The genera arrange themselves under two 
groups (sub-orders), according as the sporogonia are terminal or 
lateral, with reference to the main axis ; the first constitute the Acro- 
carpce, including Funaria, Bryum, Mnium, Polytrichum, etc. ; those 
with, lateral sporogonia constitute the Pleurocarpm, and include Fonti- 
nalis, Glimacium, Hypnum, etc. 

In the Tertiary of Europe the order is represented by an Eocene spe- 
cies of Musettes, and Miocene species of the modern genera Fontinalis, 
Bicranum, Barhvla, Polytrichum, Hypnum, etc. A single species of 
Hypnum from the Tertiary of Colorado is the only American fossil of 
this order yet detected. 



The most valuable systematic works for the student of the Bryo- 
phytes of this country are " Musci and Hepaticae of the Eastern United 
States," by W. S. Sullivant, 1871; " Icones Muscorum," by the same 
author, 1864-74 ; and "Catalogue of Pacific Coast Mosses," by L. Les- 
quereux, 1868; " Manual of the Mosses of North America," by Leo 
Lesquereux and Thomas P. James, 1884; "Descriptive Catalogue of 
the North American Hepaticse North of Mexico," by L. M. Under- 
wood, 1884. 



CHAPTER XIX. 

PTERIDOPHYTA. 

467. — The plants of this Division constitute tlie so-called 
Vascular Cryptogams. They present an alternation of sexual 
and asexual generations, much as in the Byrophytes, but in 
the higher orders it shows signs of disappearing. The first 
generation proceeds directly from the germination of the 
spore ; it is made up of simple tissues, and is usually short- 
liyed ; it bears the sexual organs, and hence is called the 
sexual generation. The second generation,- which results 
from the fertilization of a germ-cell developed upon the 
preceding one, is long-lived, and made up in most cases 
of tissues of a high order, and the plant-body is differen- 
tiated into root, stem, and leaves ; upon this second genera- 
tion spores arise asexually year after year, and from these 
spores the sexual generation is again produced. 

468. — The sexual generation, called the Prothallium, is 
generally a flattened thallus-like growth, somewhat resem- 
bling the plant-body of the lower Bryophytes. It is always 
small, and composed throughout of parenchyma disposed in 
one, or at most a few layers ; on its under surface it generally 
produces root-hairs (rhizoids), which serve to fix it to the 
ground, and doubtless also serve as organs of nutrition. 
The cells of the prothallium are in most cases richly sup- 
plied with chlorophyll, by means of which they elaborate 
material for its growth. 

469. — When the prothallia have become sufficiently large, 
they develop the sexual organs, the antheridia and arche- 
gonia. These are formed in essentially the same manner as 
they are in the two lower orders of Hepaticae {RicciacecB and 
Anthocerotece). They are more or less imbedded in the snr- 



362 BOTANY. 

face of the prothallium, and consist of masses of cells, enclos- 
ing in each case a single cell, which develops into one germ- 
cell (in the archegonia), or a number of sperm-cells (in the 
antlieridia). The sperm-cells produce spirally coiled sperma- 
tozoids, which fertilize the germ-cell by ])assing down the 
icanal in the neck of each archegonium. In many of the 
plants of this division there is a strong tendency toward 
dioeciousness in the prothallia, and in the higher genera it 
becomes the invariable rule. 

470. — The result of fertilization is the formation of a 
young plant, by the growtli and successive division of the 
fertilized cell. In its first stages the new plant is usually 
quite simple, but it soon becomes, in the greater part of the 
Division, a leafy plant with highly developed tissues. After 
a greater or less period of vegetation the new plant produces 
spores by the internal cell-division of certain mother-cells, 
each of the latter producing four spores. The particular 
structure of the spore-bearing organs and the place of their 
appearance are quite different in the different classes. In 
many cases they are jDroduced upon the surface of the 
ordinary green leaves, in other cases upon modified leaves, 
while in still others upon the bases of the leaves, in their 
axils. The spores are in most cases of one kind, but in. 
certain genera there are large spores (macrospores), and small 
ones (microspores). 

471. — True roots first make their appearance in this 
division. A root is developed upon the young plant, but 
this never attains a great size, and others form in acropetal 
order upon the stem, and even occasionally upon the leaves. 

472. — In the Pteridophytes the three tissue systems — epi- 
dermal, fibro-v.ascular, and fundamental — attain a good de- 
gree of development. The epidermis is distinct, and con- 
tains stomata similar in form and position to those of the 
Phanerogams. In many cases there is a strong development 
of trichomes, as in the Ferns, where the young leaves are 
usually densely covered with scurfy hairs. The fibro-vascu- 
lar bundles are always closed, and generally are what De 
Bary calls concentric bundles ; in the Equisetinae, however, 
collateral bundles occur, and in Lycopodinae radial bundles. 



EQUISETIN^. 363 

The bundles vary considerably as to the tissues they contain, 
but they generally possess tracheary and sieve tissues ; the 
former is usually well-developed as spiral, scalariform, or 
pitted. Sieve tissue is, as a rule, not so well developed as 
the former, consisting for the most part of thin-walled, 
elongated cells, in which the characteristic sieves are less 
regularly formed. Fibrous tissue occurs only to a limited 
extent as a constituent of the fibi'o-vascular bundles. Paren- 
chyma is also found in them, but, like tlie former, it is 
usually not abundant. The fundamental system of tissues 
includes various forms of parenchyma and sclerenchyma ; 
the latter, however, is frequently wanting. Collenchyma and 
laticiferous tissue are not found in the greater part of the 
Division ; but the former occurs in Marattiacese, in which or- 
der, according to Sachs' observations, there are also indica- 
tions of a rudimentary laticiferous tissue. 

§ I. Class Equiseti^^. 

473. — In the plants of this class the plant-body (of the 
asexual generation) consists of a hollow elongated and jointed 
axis, bearing upon each node a whorl of narrow united leaves, 
which form a close sheath [s, Fig. 249) ; the stem is always 
grooved or striate, and is usually rough and hard from the 
large amount of silica deposited in the epidermis. The 
branches arise by the side of the axils of the leaves consti- 
tuting the sheaths, and consequently they are in whorls. 
Both the main axis and the branches are in most cases richly 
supplied with chloro2:)hyll-bearing parenchyma ; in some of 
the species {e.g., Equisetum Telmateia and E. arvense) the 
stems which bear the spores are destitute of chlorophyll. 
All the species develop numerous colorless branching under- 
ground stems, which bear roots and rudimentary sheaths, 
and which each year send up the vegetating and spore- 
bearing stems. Both root and stem grow from an apical cell. 

474. — In common with most members of th^'s division, 
the Equisetinae are perennial plants. In some ispecies the 
underground portions only persist, the aerial stems dying at 
the end of each year, as is the case in E. Telmateia, E. arvense^ 



864 



BOTANY. 



E. sylvaticiim, E. limosiun, and some other species. In 
other si)ecies, as E. hyemale, E, Icevigatum, the aerial stems 
also persist; the latter are hence known as perennial- 
stemmed. 

475. — Tlie prothallia are irregularly branched thallus-like 
growths, composed of chloroiihyll-bearing parenchymatous 
cells arranged in one or more layers. Upon tlie under side 
they bear root-hairs, which fix them to the ground. They 
are usually small in size, ranging from two or three to ten or 
twelve mm. in length. In most species the prothallia are 
dia3cious, bearing but one kind of 
sexual organ upon each, and in such 
cases it always happens that those 
which bear the antheridia are much 
smaller than those which bear arche- 
gonia. Both kinds live but for a 
short time, the whole j^eriod of their 
existence usually not extending be- 
yond a few months ; the male pro- 
thallia apj)ear to endure for a some- 
what shorter joeriod than those which 
bear archegonia. 

476. — The antheridia occur upon 
the ends or margins of the prothal- 
lia ; they arise from the rejieated 
a marginal cell, thus 
forming an inner mass of cells rich 
in protoplasm, and a coYeriug layer 
{cm', Fig. 250, A). By the continued division of the inner 
cells 100 to 1§0 cubical cells are formed, each of which con- 
tains a single sperm-cell ; somewhat later the walls of the 
cubical cells dissolve, and the sperm-cells become free in the 
antheridial cavity, from which they are soon allowed to es- 
cape by the separation of the apical cells of the enyeloping 
layer {an, Fig. 250, A). At this time each sjDerm-cell con- 
tains a spermatozoid, which soon escapes by the rupture of 
the cell-wall. Each spermatozoid is a~ thick, spirally coiled 
filament of protoplasm, tapering anteriorly, where it is pro- 
vided with numerous cilia, which give it motility. 




Fig. 249.— Portion of tlie up- 
right stem of Equisetum Tel- 
mateia (nat. size), i, i, inter- 
nodes ; A, central hollow space 
of internode ; /, air spaces (la- 
cunae) in the cortex ; s, sheath cLiyigion of 
of united leaves ; z, their sep- 
arate apices (teeth) ; a, a', a'^, 
basal internodes of lateral 
branches.— After Sachs. 



Eq UlSETINM. 



36{ 



477. — The arcliegonia arise upon the anterior edge of the 
prothallium, from the division of single cells. The mother- 
cell of the archegonium undergoes several divisions, result, 
ing in the formation of a germ-cell, surrounded by one or 
more layers of cells. The germ-cell lies at a considerable 
depth beneath the general surface of the prothallium, above 




Fig. 250. — A, fragment of a prothallium of Equisetum limosum (in the middle of 
July) ; a, an apical cell of a growing point ; an, a ripe antheridium, with escaping 
sperm-cells ; an', a young antheridium. B, longitudinal section of an archegonium 
of Equisetum arvense immediately after the opening of its apex^ sliowing the germ- 
cell in the cavity below, surrounded by the parenchyma of the prothallium. C, longi 
tudinal section of the germ-cell, or rudimentary embryo, of E nrvense, shortly after 
fertilization ; it is seen to be already divided into four parts, and the whole is sur- 
rounded by the parenchyma of the prothallium. A X 200 ; B and C X 300.— After 
Hofmeister. 



which the surrounding tissue of the archegonium is pro- 
longed into a four-sided tube. At the period of maturity of 
the archegonium, the projecting cells diverge from each 
other, and form an open channel to the germ-cell {^B, Fig. 
250). 

478. — After fertilization the germ-cell undergoes division 



366 



BOTANY. 



into four cells {C, Y\g. 250), and from these the young plant 
of the asexual generation is developed. The young plant is 
quite simple, having small internodes, bearing sheaths which 

contain but three leaves ; lar- 
ger shoots soon arise, with lar- 
ger internodes and sheaths hav- 
ing more leaves, and these are 
followed by others still large)-, 
until at last the full size is 
reached. 

479. — Tlie spores of the 
Equisetinse are produced either 
upon the ordinary green stems, 
as in Equisetum limosiim and 
E. hyemale, or upon colorless 
or brownish stems, which de- 
velop early, and, after bearing 
the spores, die and disappear, 
as in E. Telmateia and E. 
arvense. The sporangia are 
developed upon modified 
leaves, upon the ends of the 
stems. The spore - bearing 
leaves, like the ordinary ones, 
are in whorls ; each leaf is, 
however, peltate in form, and 
borne upon a short stalk (s^, 
Fig. 251, B). These peltate 

leaves (usually called the pel- 
Fig. 2bl.— Equisetum Telmateia. A, x - opqlpo\ o^p pollppfprl infn 
upper part of a fertile stem, with lower ^^^^ SOaies; are COlieCcea lUtO 

Sfrd^eSSi':;:j;Lfr^^';.in|trm! cone-shaped clusters, and by 
L'etiiS'S^tttrSwSiafe W^eir nintnal pressure each 

been cut off ; tj, section of the rachis of scalc bcCOmeS morC Or leSS 
the spike. B, peltate scales, 5, 5, in . 

various positions (slightly magnified) ; llCXagOnal in OUtlmC. Upon 

sg.thQ sporangia borne on the under side , , -, „ <? i i 

of the scales ; st, st, the pedicels of the the Unclcr SUriaCC 01 eacll SCaiO 

scales.— After Sachs. , i • ix ^ • x 

there arise nve to nine or ten 
cellular masses, which enlarge and become sac-shaped spo- 
rangia ; certain inner cells become spore mother-cells, and 
from each of these four spherical spores are produced. The 




EQUISETm^. 36? 

sporangia, when mature, aj)pear as nearly cylindrical sacs 
attached by one end to the under surfaces of the peltate 
scales {sg, Fig. 251, B); they open at maturity by a slit along 
the inner face — i.e., the side next to the pedicel of the pel- 
tate scale. 

480. — In their development the spores acquire three con- 
centric coats, and as they aj^proach maturity the outer one, 
which has preyiously become spirally thickened, splits from 
two opposite points into four narrow spiral filaments, which 
are united with one another and the spore at a common 
point. These filaments are hygroscopic, and they roll and 
unroll with the slightest changes in the moisture of the air : 
when moistened they wrap tightly around the spore, but 
when dry they unroll and become more or less reflexed. By 
the changes of position which they undergo, they move the 
spores very considerably, and are doubtless useful in empty- 
ing the sporangia after dehiscence — hence they have been 
called Elaters. 

481. — The spores germinate soon after falling upon water 
or moist earth ; they first enlarge, and then divide by a par- 
tition into two parts of unequal size, the larger of which 
contains chlorophyll granules, while the smaller one is color- 
less ; the latter grows rapidly into an elongated root-hair. 
The larger cell divides first into two cells, and then usually 
one of these divides again, and so on, giving rise to a simple 
prothallium, composed of a single layer of cells ; this en- 
larges and increases in size, until it reaches the stage in 
which it bears the sexual organs (paragraph 475). 

482. Tissues. — The epidermis is remarkable for the large 
quantity of silica which it contains, mainly in the outer 
walls of the cells. The epidermal cells are mostly narrow 
and elongated, and are arranged in vertical rows. The sto- 
mata, which are present in all the chlorophyll-bearing parts 
of the plant, are arranged with more or less regularity in 
longitudinal rows ; on the stem they occur in the channels 
between the numerous ridges. They resemble pretty closely 
the stomata of the Phanerogams in their structure. The 
fibro-vascular bundles of the stem are disposed in a circle, as 
seen in a cross-section, and they run through the funda- 



368 BOTANY. 

mental tissues from node to node, parallel with, but inde- 
pendent of, one another. At the nodes they split into two 
blanches, which unite right and left with corresponding 
branches of other bundles, and thus form the bundles of the 
next internode. The bundles of successiye internodes thus 
alternate with one another. Each leaf of the leaf-sheaths 
sends down a bundle, which joins a bundle in the stem at 
the point where two descending branches of contiguous bun- 
dles from the U23per internode unite to form a bundle in the 
lower internode. The bundles are thus seen to be of the 
"common" type — i.e., they are common to both stem and 
leaves. As to their construction, they are collateral, and 
contain tracheary, sieve and fibrous tissues (paragraph 139, 
and Fig. 99). The remainder of the stem (the fundamental 
portion) is made up for the most part of parenchyma ; in the 
cortical j^ortion of the vegetating shoots it contains an 
abundance of chlorophyll, and it is here frequently pene- 
trated by large longitudinal canals {I, Fig. 249) ; in the 
medullary portion a great central canal soon appears by the 
rapid growth causing a rupture of the tissues {h, Fig. 249). 
There are frequently found in tlie hy|)odermal portions of 
the fundamental systems bands of thick-walled tissue, which 
are either sclerenchymatous or fibrous. 

{a) This class contains but one living order, the EQUiSETACEiE. hav- 
ing the characters of the class as given above. In ancient geological 
times the Calamites and their allies constituted a distinct order, the 
GalamaHem, now extinct ; they differed from the Equisetacem in hav- 
ing fibro- vascular bundles which increased exogenouslj. The Cala- 
mariecB were represented in the Devonian by a species of AsierophyU 
li'cs. In the Carboniferous period there were many species of the gen- 
era Calamites, Galamndadus, Ca'amostacliys, SphenopJiyllum, etc. In 
the Permian the order became extinct. 

(&) The order Equisetatem includes but a single genus, Equisetum, 
which contains about twenty-five species. None of the species attain 
a great size, the usual height being from 20 to 100 cm. (8 to 40 inches) ; 
one species {E. giganteum) in tropical South America attains a height 
of 9 to 10 metres (30 feet or more), but it is very slender, being no more 
than 20 to 25 mm. (1 inch or less) in diameter. The silicious stems of 
E. Tiyemale, a common species, are sometimes used for scouring knives 
and other articles. 

(«) The germination of the spores of Equisetinse may be studied by 



FILIGIN^. 309 

placing- fresli spores in water, or upon moist earth or moist pieces of 
porous pottery. It must, however, be borne in mind that within a few 
days after reaching maturity the spores lose their power of germinating-. 
{d) The oldest genus of this order is Equisetites, represented in the 
Carboniferous by several species. Equisetum extends from the lower 
Secondary (Triassic) to the present. 

§ II. Class Filicik^. 

483. — The plant-body of tlie asexual generation in this 
class consists of a solid stem, bearing roots and broadly ex- 
panded leaves, the latter usually on long petioles. The 
stems are mostly horizontal and underground, but in some 
cases they rise to a considerable height vertically in the 
air. The leaves arise singly upon the stems, and grow up- 
ward from the rhizome (horizontal stem), or are borne as a 
crown upon the more or less elongated upright stem. The 
leaves are in nearly all cases supplied with fibro- vascular 
bundles, which run as veins through the parenchyma ; there 
is usually a prominent midrib, upon each side of which the 
parenchyma is permeated with small veins, which are free 
(running more or less parallel from the midrib to the margin), 
or reticulated. 

484. — The Filicinse are for the most part terrestrial plants 
of considerable size, a few only being small or of an aquatic 
habit. They are all richly supplied with chlorophyll, and 
none are in any degree parasitic. Nearly all the species are 
perennial, in some cases, however, dying down to the 
ground at the end of the summer, the underground portions 
alone surviving the winter. 

485. — The prothallium in the Filicinge is a small cell- 
ular body,* composed in most cases of chlorophyll -bear- 
ing parenchyma. It is frequently somewhat heart-shaped, 

* Dr. Farlow, in a paper on "An Asexual Growth from the Pro- 
tliallus of Pteris cretica," in Proa. Am. Acad. Arts mid Sciences, 1874, 
and Qr. Jour. Mic. Science, 1874, described certain prothallia in which 
scalariform vessels were found by him. These abnormal prothallia 
produced new plants directly, without the intervention of the usual 
process of fertilization ; the scalariform vessels of the prothallia were 
in every case continuous with those in the new plants. 



370 



BOTANY. 



and is generally provided with root-liairs on its under sur- 
face, by means of whicli it secures nourishment for its inde- 
pendent growth (Fig. 252). In the RMzocarpem the pro- 
thallium is so reduced as to be only a small outgrowth of the 
germinating spore. 

486. — Both kinds of sexual organs usually occur upon the 
same prothallinm. The antheridia consist of a few or many 
sperm- cells, which may or may not be surrounded by a wall 




Fig. 252.— A prothallinm of a fern, seen from the under side, h, the root-hairs grow- 
ing from the basal end of the prothallinm ; an, the antheridia scattered among the 
root-hairs ; ar, archegonia near the apex, x 10.— After Prantl. 

Fig. 253.— Mature antheridium of ^c?mn^Mm Capillus- Veneris, p, cells of prothal- 
linm ; a, wall of antheridium— the sperm-cells are seen escaping, in each a sperma- 
tozoid is coiled up ; s, the spermatozoids ; b, the protoplasm of the sperm-cells still 
attached to the spermatozoids. x 550.— After Sachs. 

of other cells. In the Ferns (Filices) they are few-celled 
bodies, which project from the basal portion of the under 
surface of the prothallinm ; one of the interior cells becomes 
divided into sperm-cells, in each of which is a spirally coiled 
spermatozoid (Fig. 253). In the other orders the antheridia 
are not confined to the under surface of the prothallinm, and 
in some of the Rliizocarpece nearly the whole of the contents 
of a microspore is developed into one antheridium filled 
with sperm-cells. 



FILICINJEJ. 



371 




Pig. 254.— Young archegonium 
of Pteris se7Tulata, showing a few 
cells of the prothallium, contain- 
ing chlorophyll, and the axial row 
of cells and the germ-cell, filled 
with dense and granulated pro- 
toplasm. Highly magnified, — 
After Sachs. 



487. — The archegonia of the Ferns are celhilar projec- 
tions from the anterior portion of the under surface of the 
prothallium. The germ-cell is sit- 
uated at the base of an axial row 
of cells ; the latter dissolve^ and thus 
form a canal, which becomes open 
by the separation of the apical cells 
of the archegonium wall (Fig. 254). 
The archegonia of the other Fili- 
cinse do not differ much as to struc- 
ture, but like the antheridia, they 
are not confined to the under sur- 
face of the prothallium. 

488. — After fertilization the 
germ-cell divides (in the known 
cases) into four parts, as in Equi- 
setinm, and by the growth and development of these the 
young plant of the asexual generation is produced. The 
young plant is at first very simple, the 
first leaves being much smaller and less 
divided than those which appear later 
(Figs. 255 and 256). 

489. — The spores are developed upon 
the leaves. They are contained in spo- 
rangia, which occur singly or in clusters 
upon the surface, or on the margins of 
the more or less modified leaves ; in one 
order, the Opliioglossacem, the single spo- 
rangia occur in the tissues of the greatly 
modified leaves. The spores are all of one 
kind, excepting in the Bliizocarpem, in 
iium° and young plant of which there are two sizes, viz., micro- 

Adiantum Capillus-Ven- 

eris, seen from below, sporcs and macrosporcs. The sporangia 

p, the prothallium ; A, j. , , , -^ • j. 

root-hairs of prothallium; 01 the trUC T CmS {J^tllCeS) liavc a YlUg 01 

pian[- w'^\e^&mrToot cclls belonging to their walls, peculiarly 
^L^^seconrroSt "" X I- thickened, forming an elastic ring, which 
After Sachs. rupturcs the mature sporangium ; in the 

other orders there is no such elastic ring, and the dehiscence 
is usually by the simple splitting of the dried wall. 




Fig. 255. — Prothal- 



372 



BOTANY. 



490. — The Filicinse may be here arranged under four 

orders, as follows :* 



/. IsosporecB. — 
Spores of one 
kind. 

Order 1. Filices, 

the true Ferns. 
Sporangia compos- 
ed of modified tri- 
chomes, each de- 
veloped from a sin- 




Fig. 256.— Prothallium and _ young plant 
antum Cajnllus- Veneris, seen 
section. ^9, 2?, the prothallium 
hair ; E, the young plant ; w, its first root 
leaf. X about 10.— After Sachs. 



Adi- 
m vertical longitudinal 
a, archegonia ; h, root 



b, its first 



gle epidermal cell, produced in clusters on the surface of or- 
dinary or slightly modified 
leaves. Each sporangium 
with an elastic ring, l^o stip- 
ules. 

Order 2. Marattiacese, the 
Eingiess Ferns. Sporangia 
produced from a group of epi- 
dermal cells ; the ring either 
rudimentary or wanting. The 
large, much - branched leaves 
with stipules. 

Order 3. Ophioglossacese, 
the Adder-Tongues. Sporan- 
gia formed by groups of cells 
in the interior of a modified 
branch of the sheathing leaf. 
The ring is absent. 

//. HeterosporecB. — Spores 
of two kinds. 

Order 4. Rhizoearpese, the 
Pepperworts. Sporangia com- 
posed of modified trich- 
omes (?); the microsporangia 
containing many microspores, 

* This arrangement is essentially that modification of Sachs' pro- 
posed by Professor McNab. See his " Outlines of the Classification of 
Plants," American edition, Chapter VII. 




Fig. 257.— -4, a ti'ansverse section of 
the stem (rhizome) of Pteris aquUina, 
slightly enlarged, r, brown sclerenchy- 
ma, forming a hard theath beneath the 
epidermis ; p, colorless parenchyma of 
the fundamental system ; ig, inner fibro- 
vascular bundles ; ag, the broad upper 
band of the outer bundle zone ; pr, a 
band of elongated thick-walled cells, 
sclerenchyma or fibrous tissue— a second 
one occurs on the other side of the cen- 
tral bundles. JB, the separated upper 
fibro-vascular bundle of the stem (rhi- 
zome), st, and its branches, st', st" ; b, 
bundles of the leaf stalk ; v, v, u, out- 
line of the stem.— After Sachs. 



FILIOES, 



373 



I 



the macrosporangia usually containing only one macrospore. 
Sporangia in clusters, enclosed in modified leaves or 
^'-fruits." 

Order Filices, the true Ferns. The prothallia of the Ferns are 
green thallus-like structures, growing upon the surface of the ground. 




Fig. 257«.— Longitudinal section of the apex of the root of Pterls hastata. », 
apical cell ; o, o, epidermis ; e, cortical tissue ; c-c, c-c, the primary fibro-vascular 
bundles ; n, m, I, k, the root-cap ; k, k, daughter-cells recently cut oft' from the apical 
cell.— After Nageli and Leitgeb. 

and composed at first of but a single row of cells, but later of extended 
layers of cells. They are monoecious, and bear tlieir antheridia on the 
basal portion of tht- under surface, while the archegonia are found near 
the apical margin of the same surface. After fer 
tilization the germ-cell divides into four parts, the 
uppermost one (or two) of which becomes the foot, 
or organ which remains in contact with the prothal- 
lium ; one of the other parts develops into the first 
root, and the other into the first leaf. The young 
plant is thus formed on the under side of the pro- 
thallium, from which it grows up as shown in Figs. 
256 and 255. 

The stems of Ferns are mostly short, or slender 
and creeping in our species, but in the tropics they 
are often of considerable height and thickness, 
some tree-ferns attaining the height of 24 metres 
or more (80 feet or more). They increase in length 
only, and this takes place by the continued division of an apical cell 
They contain flat fibro-vascular bundles (Fig. 257, A and B), which are 
usually disposed in a single circle, as seen in a cross-section, but in 
some cases there are bundles in the medullary portion also. On ac- 
count of the presence of thick masses of thick- walled cells, (scleren- 




Fig. 2576.— Portion 
of under surface of a 
leaf of PolyjMdium, 
showing sori.— From 
Le Maout and De- 
caisne. 



374 



BOTANT. 



cliyma, or fibrous tissue), the stems are frequently very liard. Tlie 
fundamental tissues frequently develop a good deal of mucilaginous or 
slimy matter. 

Both stems and roots develop from a three-sided apical cell. The 
apical cell of the root continually undergoes fission not only parallel to 
its sides, but also parallel to its base — i.e., at right angles to the axis of 
the root. The daughter-cells thus cut off (/<;, k. Fig. 257a) constitute the 
root-cap {pileorldza) with which each root-tip is covered. 

The leaves, which unfold circinately, are often very large, and in 
most cases are more or less lobed and divided, frequently becoming 
several times compound. Their development is slow, the rudiment of 
the petiole forming one year, and that of the blade the next, while the 
opening or unfolding does not take place till the following year. The 
growth is sometimes periodic, as in Qleichenia and Lygodium. In the 





Fig. 258. 



Fig. 259. 



Fig. 260. 



Fig. 258.— Under side of a fertile leaflet of Aspidium Filix-mas, with eight sori. 
i, the indusium. Magnified. — After Sachs. 

Fig. 259.— -A leaflet of Asplenium, showing the elongated sori, each covered by a 
laterally placed indusium.— From Le Maout and Decaisne. 

Fig. 2tj0.— A leaflet of Adiantum, showing the sori covered by indusia formed by 
reflexions of the margin of the leaflet. — From Le Maout and Decaisne. 

latter the leaf eventually becomes greatly elongated, resembling a 
climbing stem. 

The sporangia are usually formed in clusters {so7'i) on the veins, on 
the under side of the leaves, or upon their niargins. The sori may 
be distinct and rounded or more or less elongated, or they may be 
confluent over considerable portions of tlie surface. In some cases 
the sori are naked (as in Fig. 2576), but quite frequently each one 
is covered by a cellular outgrowth of the leaf, called the indusium 
(Figs. 258, 259, 260). In some cases the indusium is shield-shaped, its 
short pedicel arising in the midst of the sporangia (Figs. 258 and 261) ; 
in others it is more or less elongated, and attached by one of its edges 
to the side of the sorus (Fig. 259) ; in still others a portion of the mar- 
gin of the leaf is reflexed in such a way as to form the covering (Fig. 260). 
Many other forms are common, and are to be found described in system- 
atic treatises. The sporangia are more or less rounded bodies, usuaJy 



FILICES. 375 

borne upon slender pedicels. Morpliologically they are tricliomes, 
wliicli undergo a special modification. Each sporangium is at first a 
two-celled tricliome ; the lower cell of which develops into the pedicel, 
while the other becomes divided by partitions parallel to its surface 
into outer cells, which develop into the sporangial wall, and an inner 





Fig. '2,Q\.—Aspidium Filix-mas. A, a section of a leaf through a sorus ; s, 9, the 
sporangia, borne upon an elevated mass of tissue, the receptacle ; i, i, the indusium, 
seen in section. £, a section of a young sporangium, showing its central cell divided 
into four ; r, one cell of the ring, the section being at right angles to its plane. C, a 
sporangium nearly mature, seen laterally ; r, ?\ the ring of the sporangium ; d, a 
glandular hair— in the interior of the sporangium are seen the nearly ripe spores. 
Magnified.— After Sachs. 



tetrahedral cell (the so-called central cell), rich in protoplasm ; from the 
latter a number of spore mother-cells (twelve, according to Reess) are 
formed, and from each spore mother-cell four spores arise (Figs. 361 
and 262). In each sporangium some of the cells of the wall are devel- 
oped into an elastic ring (annulus), which extends part way around the 



376 



BOTANY. 



spore cavity (Fi<^. 2G1, C, r). By the contraction of this ring the ripe 
sporauginni is ruptured and the spores set free. In some cases, instead 
of forming a ring, tlie elastic cells are arranged as a group at one side 
or end of the sporangium. 

Six families or suborders of the Ferns may be distinguished, if we 
take into consideration the characters derived from the asexual genera- 
tion. They have been arranged as follows : * 

1. Oleicheniacem. — Sporangia sessile, splitting vertically, furnished 
with a complete horizontal ring. Sori composed of very few sporangia ; 
receptacle not elevated (Fig. 263). Fronds with very distinct dichot- 
omous branching. Genera two {Platyzoma and Oleichenia) ; species 
thirty, mostly confined to the southern hemisphere. 

2. Hymenophyllaceoi. — 
Sporangia sessile, split- 
ting vertically, furnish- 
ed with a complete 
horizontal ring. Sori 
composed of numerous 
sporangia inserted on a 
long filiform receptacle 
(Fig. 264). Leaves of 
filmy texture (usually of 
a single layer of cells), 
with pinnate branching. 
Genera two {Hymeno- 
phyllum and Tridioma- 
nes) ; species 150 to 200, 
mostly confined to the 
tropics. 

3. Gyatheacem. — Spo- 
rangia nearly sessile, 
splitting transversely. 




Fig. 262.— Development of the spores of Aspidium 
Filix-mas. /., a mother-cell containing a nucleus; 
//., the same after the absorption ot the nucleus ; 
III., the mother-cell, with two large clear nuclei— 
sometimes a line of stparation is evident, as in the 
figure ; IV., the mother-cell, with four clear nuclei, 
w^ich appear after the absorption of the two in 
///. ; F., the four daughter-crlls (young spores) 
M'hich form from IV.; VI, VII., VIII, different 
relative positions of the developing spores ; IX., the 
perfect spore, x 550.— After Sachs. 



* The characters and arrangement of the suborders of ferns are 
taken from the article " Ferns," by W. T. T. Dyer and J. G. Baker, in 
the " Encyclopaedia Britannica," ninth edition, Vol, IX., p. 104. For a 
systematic account of the Ferns the student is referred to " Synopsis 
Filicum : a Synopsis of all Known Ferns," by W. J. Hooker and J. G. 
Baker, London, 1873. The student may profitably consult the following- 
recently published American works, viz," The Ferns of North America,** 
by D. C. Eaton, the plates by J. H. Emerton, now being issued in parts ; 
''Ferns of Kentucky/' by John Williamson, 1878; "Ferns in Their 
Uomes and Ours," by John Robinson, 1878 ; and ** Ferns of the South- 
west," by D. C. Eaton, in Lieut. Wheeler's " Report upon U. S. Geo- 
graphical Surveys West of the One Hundredth Meridian," Vol. VI., 
1878 ; Underwood's " Our Native Ferns, and their Allies," 1888. 



FILIGE8. 



377 



furnislied with a usually incomplete, nearly vertical, or rather oblique 
ring. Receptacle prominent, barrel-shaped (Fig. 265). Tree-ferns. 
Genera three {Cyathea, Hemitdia, and Alsophila) ; species 150, mostly 
tropical and subtropical. 

4. Polypodiacem. — Sporangia stalked, splitting transversely, fur- 
nished with a usually incomplete vertical ring. Receptacle not prom- 




FiG. 263. 



Fig. 264. 



Fig. 265. 



Fig. 263.— Portion of a leaf of Gleich&nia, with a sorus, a ; b, a sporangium. — Af- 
ter Hooker. 

Fig. 264.— Portion of a leaf of Trichoinanes, a, with five sori ; b, a sporangium. — 
Aftf r Hooker. 

Fig. 265.— Vertical section of a sorus, a, of Alsophila, showing the cylindrical re- 
ceptacle ; 5, a sporangium. — After Hooker. 



inent (Figs. 257& to 261). Genera fifty (Acrostichum, Polypodium, 
Adiantum, Pteris, A,splenium, Scolopendriu7n, Aspidrim, Cysiopteris, 
etc.); species 2000, widely distributed throughout the world, 

5. OsmundacecB. — Sporangia stalked, splitting vertically, furnished 
with only a faint horizontal bar, instead of a ring (Fig. 266). Genera 
two {Osmunda and Todea) ; species ten to twelve, widely distributed in 
north and south temperate re- 
gions. 

6. Schizceacece. — Sporan- 
gia sessile, splitting vertical- 
ly, crowned by a complete 
small annular horizontal ring 
(Fig. 267). Genera five 
{ScMzcea, Anemia, Lygodium, 
etc.); species sixty, mostly 
natives of the warm regions 
of America and Asia, 

Economically the true Ferns are of comparatively little value. The 
pulpy interior of the stem of a tree-fern {Cyatliea medullaris) growing 
in the Pacific islands furnishes an important article of food to the 
natives. In Australia the underground stems of Pteris aquilina 
supply an indifferent food. A few species are of doubtful value as 
astringent medicines. The long woolly hairs of certain species ot 




Fig. 267. 

Fig. 266. —'Two sporangia of Osmunda; a, 
with the rudimentary ring peen in front view ; 
b, with the ring seen in profile.— After Hooker. 

Fig. 267.— Lower portion of a fertile iiinna, a, 
of ScMzcea ; b, a sporangium.— After Hooker. 



378 



BOTANY. 



Dicksonia growing in the Sandwich Islands constitute the substance 
known as Pulu, used somewhat in upholstery. Many of the species 
are now largely grown as ornaments. 

Ferns first appeared in the Devonian, in which period no less than 
twelve <reuera belonging to extinct families were represented. In the 
Carboniferous the genera and species were exceedingly numerous, after 
which they decreased to the i)resent. Many Tertiary genera extend to 
the present, and are now represented by living species. 

Order Marattiacese, the Ringless Ferns. The prothallia of the 
ringless Ferns are thick, fleshy, and dark green in color. They bear 
antheridia in depressions upon both surfaces, and in these are pro- 
duced sperniatozoids bearing much resemblance to those of true Ferns. 
The archegonia are also deeply sunken in the tissue of the prothallium, 
and, according to M-Nab, resemble those of the Rhizocarpeae. 

The asexual generation bears a close resemblance to that of true 




Fig. 269. 



Fig. 268.— A prothallium of BotrycMum Luiiaria, in longitudinal section, ac, an 
archegonium ; an, an antheridium — near to it are others, one not yet mature, and 
three empty ones ; w, root-hairs. X 50.— After Hofmeister. 

Fig. 269.— A longitudinal section of the lower part of a young plant of the same, dug 
up in September, st, stem ; b, h', h'\ leaves, x 20.— After Hofmeister. 

Ferns. The plant-body is usually large ; its stem is generally upright, 
short, thick, and unbranched ; the leaves are circinately developed, as 
in true Ferns, and are mostly very large, with pinnately or palmately 
divided laminae ; they are provided with stipules, and in their petioles 
is found the first collenchyma. The stem develops from a three-sided 
apical cell, but the root is provided with a group of cells, as in the 
Phanerogams, 

The sporangia occur on lateral veins upon the under side of the 
leaves, and are usually confluent into one body, the sorus (often called 
erroneously the sporangium). In Angiopteris, however, the sporangia 
are distinct. The spores develop from many mother-cells in each spo- 
rangium, instead of from one, as in true Ferns. 

The Marattiaceae are essentially tropical, extending somewhat into 
the warmer parts of the temperate zones. Four genera are known, 
viz. , DcBiima, restricted to tropical America ; Kaulfussia and Angiopteris, 



OPHLOGLOSSAGE^. 



379 



found in the tropical regions of tlie eastern liemispliere ; and Marattia. 
wliicli is represented in tbe New and Old World. The whole number 
of species probably does not exceed twenty-five. 

The oldest members of this order oc- 
cur iu the Permian strata. 

Order Ophiog-lossaceae, the Adder- 
Tongues. The prothallia of these fern- 
like plants are thick masses of paren- 
chyma, which are destitute of chloro- 
phyll ; they develop underground, and 
5)re difficult to study, hence they are 
known for but few of the species. In 
BotrycJiium Lunaria, according to Hof- 
meister,* the prothallium is "an oval 
mass of firm cellular tissue, whose larger 
diameter does not exceed a millimetre 
(one twenty-fifth of an inch), and is often 
less " (Fig. 268). He discovered them 
in the ground at a depth of from two 
and a half to seven and a half centim- 
etres (one to three inches). The an- 
theridia occur for the most part upon 
the upper surface, and the archegonia 
upon the lower. 

The mature plant (asexual generation) 
consists of a short erect underground 
stem, which bears annually one or more 
stipulate and erect {i.e., not circinate)f 
leaves (Fig. 269, ¥ and ¥\ and Fig. 
270). The leaf is usually divided into 
two portions, one of which is green and 
expanded (Fig. 270, h), while the other 
is contracted into a spore-bearing organ 
(Fig. 270, /) ; in some cases each seg- 
ment is simple, while iu others it is one 
or more times compound. 

The spores of the Ophioglossacem are 
produced from mother-cells developed in 
the tissue of tlie fertile segment of the 
leaf ; hence the so-called sporaligia of 
this order are morphologically quite 
different from those of true Ferns. 




(f 
Pig. ;370.— Plant of BotrycMum 
Lunaria, nat. size, st, st, the short 
stem ; ^o, r ots ; bs, the leaf stalk; 
a?, point where the leaf branches 
into the sterile part {b) and the fer- 
tile or spore-bearing portion (/). — 
After Sachs. 



■* " On the Germination, Development, and Fructification of the 
Higher Cryptogamia," etc., by Dr. Wilhelm Hofmeister. Translated 
by Frederick Currey, London, 1862. 

f The vernation of our species of BotrycMum is well worked out in 



380 



BOTANY, 



The stems are developed from a triangular apical cell, while the 
roots, like those of Marattiacem, possess no apical cell, but a group 
of cells instead. The fibro-vascular bundles are arranged in a cylinder 
(a circle in cross-section), and they form a network by their anastomos- 
ing with each other. According to De Bary, they belong to the ' ' col- 
lateral " series. 

These plants are usually of small size, rarely exceeding 30 centime. 




Fig. 271.— J., vertical section of an archogonijim and the rudimentary prothallium 
of Filidaria globulifera ; tv, w, part of the ruptured wall of the macrospore ; p, p, 
the rudimentary prorhallli^ra, merging above into the archegoninm ; g, the germ-cell 
ready for fertilization ; sc. the cavity of tlie macrospore. x 500. B, a microspore 
of the same burst open and allowing the escape of sperm-cells, s. from which sper- 
matozoids arc escaping, x 600. C, longitudinal section of a macrospore of Sahinia 
vatans at the commencement of germination ; p, the young prothallium. x 30. D, 
a very young prothallium of the same, detached, with a fragment of the inner spore- 
membrane (m) adhering to it— top view, x 200. E, a vertical longitndinal section of 
D. X 200. F a similar section of a more advanced prothallium of the same ; g. the 
young germ-cpll. x 200. G, vertical section of an unfertilized archegoiiium of the 
same, surrounded bv cells of the prothallium ; g, germ-cell ; a?', canal of the arche- 
goninm. x 300.— After Hofmeister. 

tres (1 foot) in heifjht ; in one Ceylonese species {OpMog''ossum pendu- 
lum) the slender pendent leaves are sometimes, according to Hooker, 
nearly three metres long (15 feet). 

There are three genera, viz. , OpMoglossum, Botrychium, and Helmin- 
thostachys ; the latter is confined to the sotithern hemisphere, the others 



G. E. Davenport's paper, Vernation in Botrychia, in the Bulletin of 
the- Torrey Botanical Club, 1878 ; it is illustrated by figures. 



ninZOCARPEM. 



381 



are cosmopolitan. All told, there are probably n?t more than eigliteen 
or twenty distinct species, of which we have six within the limits of 
the United States. 

A species of Opiiioglos.-um has been discovered in the Tertiary stratao 
Order Rhizocarpese, the Pepperworts. The prothaliia of the 
Rhizocarps are dioecious, and are developed 
from two kinds of spores (the mac ospores and 
microspores, to be more particularly described 
below). The antheridia are simple, and con- 
sist of small, few-celled outgrowths from the 
germinating microspore (in Salmnia and AzoU 
la), or of the transformed contents of the mi- 
crospore (in Marsilia and Pilularia, Fig. 271, 
B). The spermatozoids are spirally coiled, and 
in the two last-named genera are produced in 
definite numbers (thirty-two) in each antherid- 
ium. The proth^Uia which produce archego- 
nia are small, and barely attain a size large 
enough to protrude through the ruptured 
wall of the macrospore {p, p, Fig, 271, A). 
The archegonia repemble those of true Ferns, 
but are more sunken in the tissues of the pro- 
thaliia (Fig. 271, A and G). After fertiii^atioii • 
the germ-cell undergoes division, and gives 
rise directly to a leafy stemmed plant, tha 




asexual generation, provided 




Fig. 272. 



Fig. 273. 



Fig. 272.— Plant of Marsilia Drummondii. K, apex of the 
stem; fo, b, leaves; /,/, /, the fruits springing from the petioles 
at X. One half natural size.— After Sachs. 

Fig. 273. — Longitudinal section tTirough three fruits (the fer- 
tile apices of awaver-leaf) of :-alvimanat(ins. i, i, two fruits 
containing inicrotporangia ; a, one with macrosporangia. x 10. 
— ^After Sachs. 



with roots (ex- 
cept in Salvin- 
ia). The stem 
is horizontal, 
and floats upon 
the water or 
runs through 
the mud at the 
bottom of shal- 
low water. The 
leaves are cir- 
cinately devel- 
oped, and are 
simple or quad- 
rifid (Fig. 272). 
The stem and 
develop 
an apical 
which is 



root 
from 
cell, 



two or three-sided in the stem, and triangular in the root. 

The sporangia, which are usually of two kinds, are produced iu 
••fruits" or receptacles, which are modified parts of leaves. Thes© 



382 



BOTANY. 



fiuits are one-celled in Salviniacece, and several-celled in Marsiliacem. 
in Salvinia (Fig. 273) the niicrosporangia are small and numerous, and 
are contained in separate fruits from the macrosporangia, which are few 
in number ; each of the former contains many microspores, and the 
latter a siuyle macrospore (by the abortion of three, as four are formed 
at first). In Mar^ilia and Filularia the two kinds of spores occur in 
the same fruit, and in the former in the same sporangium. 

Four (renera are known ; these are arranged under two suborders or 
families, the SalviniaGede, which includes Sahirda and Azolla, and the 
Marsiliacm,w\nQ\\ includes Marsilia and Pilularia. The whole num- 
ber of species is sixty-four, of which forty belong to Marsilia, the 
others being unequally divided between the remaining genera. All 
the species are of small size, rarely exceeding a few centimetres in 
height ; they grow in ditches and other wet places. Half a dozen 
species occur in the United States. 

Rhizocarps have been found as fossils in the Secondary (Jurassic) and. 
Tertiary strata. 

§ III. Class Lycopodin^.* 

491. — The plant-body of the asexual generation consists 
of a solid, dichotomously branched, leafy, and generally erect 
stem. The leaves, which have a central fibro-vascular bundle, 
or midrib, are small, simjole, -.^ssile, and imbricated, and 
usually bear a considerable resemblance to those of Mosses. 
The roots are mostly slender and dichotomously branched. 

The Lycopodinae are for the most part terrestrial peren- 
nials. They are usually of small size, rarely exceeding a 
height of 15 or 20 centimetres (6 or 8 inches). 

492. — The spores of the Lycopodinae are produced in spo- 
rangia which are generally (if not always) axillary appen- 
dages of the leaves. In four of the genera {Lycopodium, 
Psilotum, Tmesipteris, and Pliylloglossum) the spores are 
of one kind ; while in the two remaining genera {Selaginella 
and Isoetes) they are of two kinds, the macrospores and the 
microspores. 

493. — The prothallium or sexual generation is scarcely 
known in the isosporous genera ; it appears, however, to be 
a thickish mass of tissue, which develops underground, and 

* Sachs calls this class the BicJiotomcB, but as long as we have the 
Bgmsetirice and Ftlicince,yve may, for the sake of uniformity, retain the 
old name given above. 



L TCOPODINuTJ. 



383 



bears both kinds of sexual organs. In the heterosporous 
genera the macrospores produce small protliallia, which 
project slightly through the ruptured spore-wall, and upon 
these several or many archegonia are formed ; the micro- 
spores produce very small rudimentary prothallia, each of 




Fig. 274, 



Fig. 275. 



Fig. 274.— J., longitudinal section of a young prothallium of Lycopodiwm anno- 
tinum ; aw, two antheridia, not mature— upon its lower surface are seen the root- 
hairs. X 150. B, longitudinal section of a prothallium, p, of the same, after germi- 
nation of the young plant ; s, stem of young plant ; r, its young root ; /, the foot, or 
portion of the young plant which remains in contact with the prothallium. Slightly 
magnified.— After Fankhauser. 

Fig. 275.— Plant (asexual generation) of Lyeopo'imm da'vatum; horizontal stem 
with roots and leaves, the erect branch bearing fertile spikes, s. One half natural size. 
—After Prantl. 



which" bears a single antheridium, in which there are de- 
veloped a few spermatozoids. 

494. — Three orders of Lycopodinae may be distinguished, 
as follows : 

I. IsosporecB. — Spores of one kind ; no ligules. 

Order 1. Lycopodiaeese, with small leaves, commonly* 
moss-like. 

//. Heterosporece. — Spores of two kinds ; ligules present. 

Order 2. Selaginellse, with small moss-like leaves. 

Order 3. Isoetese, with elongated grass-like leaves. 



384 



BOTANY. 



Order Lycopodiaceee. — The prothallium is known only in one case, 
vi7., Li/ro])()(l'iiiii (Diiiotin'iin). It was discovered underground by 
Fankhauser in 1872, wlio described it* as a yellowish white, irreg- 
ularly Jobed body, sparingly furnished on its under surface with small 
root-hairs (Fig. 274,^), In its upper surface the prothallium bears 

antheridia, which are 
deeply sunken in its tis- 
sue {an, Fig. 274, A); 
the spermatozoids, which 
are numerous, are stout 
and slightly twisted. 
The archegonia were 
only seen after the young 
plants had grown con- 
siderably (Fig. 274, B) ; 
they are likewise devel- 
oped upon the upper 
surface of the prothal, 
lium, and appear to bear 
a considerable resem- 
blance to those of the 
Opliioghsmcem. 

The young plant which 
results from the growth 
of the fertilized germ- 
cell is quite simple, but 
it soon takes on the form 
of the mature plant. 
The leaves are crowded 
in Lycopodium, but are 
less so in the other gen- 
era. In many species 




Pig. 276.— Germination of the spores of Selaginella. 
1, longitudinal section of a macrospore of S. Marten- 
sit : above ttie line d is tlie prothallium, below it the 
" endosperm ;" e, e', two embryos, the larger one with the sporangia are borne 
its suspsnsor projecting into the neck of the archego- 
nium ; at the left of the larger embryo is a young ar- 
chegonium ; several root-hairs are also shown. 2, a 
yonng archegonium of the same species, not yet open. 
3, an archegonium of the same species, with the germ- 
cell fertilized and divided into two. J., a microspore 
of S. caulescens^ rendered transparent, showing the di- 
vision of the contents into the primordial cells ; the 
small lower cell is the rudimentary prothallium. Z>, 
later stage of the same, showing the large antheridium 
filled with sperm-cells ; v, the rudimentary prothal- 
lium. All magnified.— After Pfeffer. 



in the axils of the or- 
dinary leaves, but in 
others the leaves which 
bear sporangia are col- 
lected into cone-like or 
spike -like structures^ 
which terminate certain 
branches (Fig. 275). The 
sporangia are more or less globose bodies, which are short-stalked 
or sessile ; they contain large numbers of small spores, which escape 
by an apical slit in the sporangium. 

* J. Fankhauser : " Ueber deu Vorkeim von Lycopodium," in Bota'Th- 
ische Zeitung, 1873, No. 1. 



BELAQINELLJS. 



385 



Four genera belong to this order, viz., Lycopodium, vf'^ixch is common 
in the wooded portions of the United States ; Psiloturn, found in 
Florida; Tmesipteris and Phylloglossum, of Australia. The species 
number from 115 to 120, of which about 100 belong to the genus 
Lycopodium. 

The spores of Lycopodium davatum are gathered in Europe and 
sold for various minor uses. Many species have a high ornamental 
value. 

This order was represented in the Devonian by species of Arctopo- 
dium. In the Carboniferous the genus Lycopodium first appeared. 

The closely related extinct order Lepidodendreae first appeared in the 
Devonian, in which it was represented by two known species of Lepi- 
dodendron ; in the Carboniferous this genus was represented by sixty or 
more species, many of gi- 
gantic size, and the order 
by many other genera — e.g., 
Lepidophloios, Lepidostro- 
bus, Ualonia, etc. la the 
Permian this order became 
extinct. 

Another order — the Sigil- 
lariese — was represented by 
many species of Sigillaria 
in the Carboniferous period. 
Like the preceding, this or- 
der became extinct in the 
Permian. 

Order Selaginellse. — 
The prothallia are dioecious. 
Those which develop from 

the macrospores consist of a spoi-e. /. 

' ,, , meister. 

concavo-convex many-cellea 

structure, which develops upon, and has its concave side applied to, the 

convex surface of the spore. Upon its convex surface, which protrudes 

through the ruptured wall of the spore, are a few root-hairs and many 

deeply sunken archegonia (Fig 276, 1, 2, 3). The microspores develop 

only the smallest rudiments of prothallia. In germination a single 

cell (-», Fig. 276, D) is first of all cut off ; this undergoes no further 

change, and is doubtless to be regarded as the prothallium. The re' 

mainder of the spore becomes divided in a regular way into a few 

large primordial cells (Fig. 276, A), and from these great numbers of 

eperm-cells are produced (Fig. 276, D). 

After fertilization the germ-cell divides at right angles to the axis 

of the archegonium (Fig. 276, 3) ; from the upper cell so formed a 

iuspensor is developed (Fig. 276, 1), while the lower develops into thn 

embryo. The embryo, by its rapid growth, comes eventually to occupy 




Fig. 277. — i., two young plants of Selaginella 
Marteiisii growing from the same spore ; at the 
top of the spore may be seen the projecting pro- 
thallium, j;. //., a young pla^t drawn out of the 
spore, showing ihe foot, /, on the left below, and 
the young root, r, on the rielit. III., a young 
plant whose first leaves (cotyledons) have been re- 
moved, leaving only their stipules, s; between the 
latter is seen the dicbotomously (WwiAin^ punctinn 
vegetationis ; p, the prothallium isolated from the 
^ X 5; //. X 3; ///. X 30.— After Hoi- 



386 



BOTANY. 



the cavity of the spore itself, in which, by bending upon itself, it lies 
at rig-lit angles to the axis of the archegonium. The new plantlet 
bears some resemblance to the embryo in the Dicotyledons ; it has an 
elongated stem, bearing at its summit two small leaves (cotyledons), 
having between them a growing bud (plumule) ; at the lower end of 

the stem there is a rudimentary 
root, and the structure known 
as the foot, which is common to 
all Pteridophytes (Fig. 277, 11). 
The young plant grows from 
the spore with its cotyledons fore- 
most (Fig. 277, /. and III.) ; this 
is only possible by the great 
bending of the embryo upon 
itself, for at first its cotyledon- 
ary extremity points directly to- 
ward the centre of the spore — 
i.e., away from the opening in 
the spore- wall. Usually but one 
plantlet grows from each pro- 
thallium but occasionally two or 
more may be developed (Fig. 
277, /.) 

The adult plant of the asex- 
ual generation is densely leafy 
throughout. The leaves are 
small, moss like, and are gen- 
erally placed in four rows, of 
which two opposite ones are 
composed of large leaves, and 
the two intermediate ones of 
small leaves. Each leaf has a 
small scale-like body, the ligule, 
on its upper surface at its base. 
The sporangia occur singly in 
the axils of certain leaves, ^en- 

Fig. 278.— A a fertile branch of *S'eZa9'^ne?^a erally in those which form the 
tnoRqmfolia, with the quadrangular spore- "^ ,^ „ .^. ., ,, ,„. 

bearing spike at the apex ; 5, vertical sec- narrower" fruitmg spikes (Fig, 

tion of the spilve, showing the microsporan- 07Q 4\ Mnr'rnQr.nrnnD-ifl ron. 

gia containing microspores on the left, and ^^^' ^^' J^^acrosporangia, COn- 

the macrosporangia with macrospores on taining four macrospores in 

the right.-A X 2 ; ^ X 15. -After Sachs ^^^^^^ usually occur in some deti- 

nite portion of the spike, as nearer the base, or upon one side (Fig. 
278, B). The microsporangia contain many microspores, and usually 
also occupy definite positions in the spike. 

But one genus, Selaginella, is known in this order ; it includes 334 
species of mostly delicate plants, which are mainly tropical, not more 




mOETEJE. 



387 



than six or seven species occurring within the limits of tlie United 
States. Many are cultivated as ornaments. 

Order Isoetese, the Quillworts. The prothallia of the Isoeteae are dioe- 
cious, and resemble closely those of SeUiginella. The macrospores give 
rise to small prothallia, which project through the triangular slit in the 
spore-wall, and bear several or many sunken archegonia (Fig. 279). The 
microspores, in their germination, first cut off a small cell ('y, Fig. 280, 
A to C), which, as in Selaginella, represents the prothallium ; the re- 
mainder of the spore contents becomes divided into four cells (the 
primordial cells), and these give rise to the sperm-cells (Fig. 280, A to 




Fig.279.— 1, Longitudin .1 section of a prothallium of Tsoefes laeustris^iovLY-weok^ 
after sowing the spore ; ar, an archegonium. 2, a poriion of the apex of a prothal- 
lium cut through longi udinally, with two archegonia, ar. ar, still in process of devel- 
opment ; g, g, the germ-cells of the arclietronia. 3, longitudinal section of an ai-che- 
gonium ready for fertilization. 4, longitudinal section of a fertilized archegonium, 
showing the germ-cell transversely divided. 5, a section similai' to the last ; in tlie 
lower cell of the embryo-rudiment preparation for division has been made by the ap- 
pearance of two nuclei. 1 x 40 ; 2 and 3 X 300 ; 4 and 5 X 400.— After Hofmeister. 



G). The spermatozoids are elongated and provided with cilia at both 
ends (Fig. 280,/). 

The germ-cell, after fertilization, undergoes transverse division 
(Fig. 279, 4 and 5), as in SelagineUa, and its subsequent development 
is essentially the same. 

The adult plant of the asexual generation consists of a very short, 
thick, tuber-like stem, which bears nunjerous long, narrow, grass-like 
leaves, which are sheathing at the base. There are also numerous 
roots. The sporangia are produced in grooves on the inner side of the 
bases of the leaves ; those attached to the outer leaves contain macro- 



388 



BOTANY. 



spores, while the iuterior ones contain microspores. Both macrospcres 
and microspores are produced in irreat numbers in the sporangia. 

The Quillworts are for tlie most part a(]uatic plants ; they are found 
chiefly in the nonh temperate and warm regions. The species, of 




Fig. 280.— Germination of the microspores of Isoetes lacustris. ji, a microspore, 
side view. B, the same, ventral view ; the spore contents have divided into a few 
cells, of which v in each figure represents the rudimentary prothallium ; j3^ ^ are the 
ventral, aud J (J the dorsal cells. C, a side view of microspore ; the four cells, R l3, 
tJj S^ have disappeared, and spermatozoids have formed. D, ventral view of C; a to 
/, development of spermatozoids. e and/ X 700, the others X 580,— After Millardet. 

which there are from forty to fifty or more, all belong to the single 
genus Isoetes;"^ we have representations of about fourteen within the 
United States. 

Two species of Isoetes occur as fossils in the Tertiary (Miocene). 



* The North American species of Pteridophytes are well described 
in "Our Native Ferns and their Allies," by L. M. Underwood. (Holt, 
•) 



CHAPTER XX. 

PHANEROaAMIA, OR ANTHOPHYTA. 

§ I. General Characters. 

498, — In this Division the alternation of generations 
which is so well marked in Bryophytes and in most Pterido- 
pliytes almost disappears. We have seen that in the higher 
Pteridophytes there is a great reduction in the size and 
importance of the prothallium (the sexual generation) ; in 
Equisetacece and Filices it is a large growth, which soon be- 
comes entirely independent of the spore from which it origi- 
nates ; in OpMoglossacem and Lycopodiacece it is of consid- 
erable size, but it is less caj^able of leading an independent 
existence ; in RMzocarpem and Selaginellm it is reduced to a 
small outgrowth of the spore ; and in Isoetece the reduction 
is still greater, the small prothallium being little more than 
the transformed spore contents. 

With the decrease in the structural importance of tb3 
prothallium in these orders of the Pteridophyta, there is a 
noticeable increase in the differentiation of the spore before 
its separation from the parent plant ; thus in the three last- 
named orders the spores have differentiated into (1) small 
ones, microspores,which are strictly male as to their functions, 
and (2) larger ones, macrospores, which are as strictly female. 

496. — In the Phanerogamia the changes begun in the 
Pteridophyta proceed a step further. The differentiation 
into male and female organs of reproduction is carried back 
far beyond the formation of the microspores (pollen grains) 
and macrospores (embryo sacs) ; the macrospore does not 
sever its connection with the parent plant, but continues to 
be nourished by it until after the embryo is formed ; and as 



390 BOTANY. 

a consequence of its maintaining its structural connection 
with the parent plant, the protliallium (endosperm) is but 
feebly developed. The prothallium is essentially, as to its 
function, a nourishing structure, which is rendered necessary 
in the Pteridophytes by the fact that the reproductive bodies 
separate from the parent plant before they are ready for fer- 
tilization ; and just as this separation is delayed, or, in other 
words, just as the parent plant bestows more care upon the 
bodies which are to give rise to the embryo, so the prothal- 
lium is less necessary, and, being less necessary, is less de- 
veloped. Thus we find a much smaller prothallium in the 
heterosporous orders of Pteridophytes than in the isosporous 
ones, and in Phanerogams, where parental care extends until 
after the formation of the embryo, there is generally only 
the smallest rudiment of a prothallium. 

497. — The leafy plant (which corresponds to the asexual 
generation of the Pteridophytes) produces two kinds of re- 
productive cells, viz., pollen grains and embryo sacs, the 
homologues respectively of microspores and macrospores. 
The j)oilen grains are for the most |)art single cells, which 
develop from mother-cells in the interior of phyllome struc- 
tures (modified leaves) ; they soon become free, and are then 
more or less spherical in shape ; they have two coats, an outer 
thick one, the extine, and a delicate inner one, the intine, 
and they contain a granular protoi:)lasm, in which oil drops 
and starch granules generally occur. The embryo sacs are 
thin-walled cells which arise axially in the ovules, structures 
which appear to be homologous to the macrosporangia of 
Pteridophytes ; they do not become free, but continue to be 
m organic connection with the cells of the surrounding tis- 
sues. Each embryo sac develops in its interior a larger or 
smaller mass of cells, the endosperm, which is the homo- 
logue of the prothallium, and in which nourishing matters 
are deposited ; it also develops one or more germ-cells, the 
homologues of the germ-cells of the archegonia in Pterido- 
phytes. 

498. — The portions of the plant-body which produce pol- 
len grains and embryo sacs are in general considerably modi- 
fied ; thus the axis is generally short, the leaves delicate or 



PHANEBOOAMIA. 391 

otherwise different from foliage leaves, and containing little 
or no cliloropliyll ; they are nsually of some other color than 
green, from tlie presence of soluble coloring-matters in their 
cells. These modified j^arts, together with the organs more 
immediately connected with the male and female reproduc- 
tive cells, constitute wdiat is known as the jiower, 

499. — The ovule, in its development, becomes surrounded 
by one or two thin cellular coats, which grow from its base, 
and almost completely enclose it, a little orifice only, the 
micropyle, being left at its apex. In the lower Phanero- 
gamia (the Gymnosperms) the ovule enclosed in its single 
(rarely double) coat is otherwise naked, while in the higher 
classes — viz., the Monocotyledons and Dicotyledons — it is en- 
closed within the cavity of the ovary, a phyllome structure, 
or, as it is commonly described, a modified leaf, which is 
folded involutely so as to form a cavity. 

500. — In the fertilization of the germ-cell there are no 
sjoermatozoids developed ; instead of producing these, the 
pollen grain develops a long slender tube, the pollen tube, 
which penetrates the tissue of the ovule, and comes in con- 
tact with the germ-cell in the embryo sac. The result of 
fertilization is always the formation of a suspensor (some- 
times called the pro-embryo) essentially like that in the 
Selaginellm and Isoetece, and, at the lower end of this, an 
embryo, consisting of a short stem, bearing generally one or 
more rudimentary leaves (cotyledons) at one extremity, and 
a rudimentary root at the other. The embryo grows at the 
expense of the endosperm, upon which it gradually en- 
croaches, and in many orders entirely displaces. While the 
embryo is forming, the ovule becomes greatly enlarged, and 
its outer coat generally much thickened and hardened ; it is 
now called the seed, and soon separates at its base from the 
parent plant. 

501. — After a longer or shorter period of rest the seed 
germinates, the root and stem elongate, and the former 
pushes out through the micropyle ; in those seeds in which 
much of the endosperm remains,* or in which the cotyle- 

* Seeds wliicli contain endosperm are, in the ordinary descriptive 



392 BOTANY. 

dons are greatly thickened, the latter remain for some time 
inside of the seed ; in other cases, however, they soon with- 
draw themselves, and become expanded as the first leaves 
of the plantlet. The young plant is quite simple at first, 
but, Avilh the development of each succeeding internode, it 
becomes more like the adult plant. 

502. — The three tissue systems are generally well de- 
veloped in Phanerogamia. The epidermis is copiously sup- 
plied with stomata, and itself consists of one or (rarely) more 
layers of cells, whose external walls are generally somewhat 
thickened, and whose cell contents rarely contain chloro- 
j)hyll. Trichomes of various forms are abundantly de- 
veloj)ed. The fibro-vascular bundles are of the form called 
by De Bary collateral bundles, the only exception being the 
first formed one in the root, which is of the radial type. 
The bundles are symmetrically arranged in the stem, through 
which they pass vertically parallel to each other. They are 
mostly common — i.e., they extend from the leaves into the 
stem ; but some are strictly cauline — i.e., they are found 
only in the stems and have no connection with the leaves. 
All the kinds of tissues, with the exception of collenchyma, 
may occur in the bundles ; but they are mainly made up of 
tracheary, sieve, and fibrous tissues. In the larger perennials, 
as the trees, the great mass of tissue in the woody stems is 
principally made up of the tracheary and fibrous tissues of 
the fibro-vascular bundles. In succulent ])lants, especially 
those growing in water, the bundles are usually smaller and 
more simple, being sometimes reduced to a thread of trache- 
ary or sieve tissue. 

In the fundamental tissues parenchyma, in its various 
forms, is by far the most common. The hypodermal por- 
tions are frequently composed of collenchyma or scleren- 
chyma. Laticiferous tissue is common in the fundamental 
system of certain orders. 

503. — By far the greater number of Phanerogams are 
chlorophyll-bearing plants, comparatively few only being 

books, said to be albuminous, while those in wliich it is wanting are 
said to be exalbuminous. 



GTMNOSPEBM^. 393 

parasitic or saprophytic. They range from minute plants 
one or two centimetres in height, and living but a few days 
or weeks, to enormous trees, which continue to grow for 
many hundred years, and Avhich attain a diameter of ten, 
and a height of one hundred metres. 

504. — The Phanerogams are se2:)arable into two classes, 
as follows :* 

Class I. Gymnospermos (the Archespermce of Strasbur- 
ger). The ovules are not enclosed in an ovary. The en- 
dosperm arises before fertilization, and forms rudimentary 
archegonia (''corpuscula"), in which the germ-cells origi- 
nate. The contents of the pollen grains divide before the 
growth of the pollen tube, forming a rudimentary pro- 
thallium, much as in SelaginellcB and Isoeiece. 

Class II. Angiospermse (the MetaspermcB of Strasburger). 
The ovules are enclosed in an ovary. The endosperm is 
formed after fertilization. The contents of the pollen grain 
remain undivided before and during the growth of the pollen 
tube. 

Sub-Class Monocotyledones.— The first leaves produced by the 
embryo (the cotyledons) are alternate ; the endosperm is usually large 
and the embryo small. 

Sub-Class Dicotyledones. — The first leaves of the embryo form a 
whorl of two {i.e., they are opposite); the endosperm is very often 
rudimentary or entirely wanting, and the embryo is generally large. 

§ II. Class Gtymkosperm^. 

505. — The plants of this class have solid stems, which 
bear in most cases small, simple, narrow leaves having a 
parallel venation. The xylem portions of the fibro-vascular 
bundles of the stem are closely compacted into a single dense 
woody cylinder, which is surrounded by a looser mass of 
tissues, the so-called bark, composed of the united jihloem 
portions of the bundles. The woody cylinder increases its 



* This is essentially Sachs' arrangement, in his " Lehrbuch," 4te 
Auf. The terms Archespermae (from the Q-reek o-px"]-, beginning, and 
therefore properly Archespermae, instead of Archispermte) and Meta- 
spermse (from juera, after or later) are those proposed by Strasburger ; 
" Die Coniferen und die Gnetaceen," 1872, p. 239. 



894 



BOTANY, 




diameter centrifugtilly, and the sheathing envelope of bark 
centripetally, by the growth of new tissues between these 

two portions. 

Gymnosperms are all ter- 
restrial, chlorophyll-bear- 
ing plants ; none are 
aquatic, and none are ^oar- 
asitic. Most of them are 
large trees, a few only 
being shrubs or under- 
shrubs. 

506. — The flowers of 
Gymnosperms are much 
simpler than those of the 
remaining Phanerogams. 
They are always diclinous 
— i.e,, the male and fe- 
male organs are in differ- 
They consist 
essentially of one or more 
variously shaped joollen-producing organs (stamens) on the 
one hand, and naked ovules on the other ; both kinds of or- 
gans are in most cases in structural connection with scale- 
like'bodies, which serve as acces- 
sory organs of reproduction. 

507. — The male flower in 
Abies pectinata consists of an 
elongated axis, upon which are 
borne a large number of spirally 
arranged stamens (a. Fig. 281, 
A). Each stamen is morpholog- 
ically a phyllome, which is here 
modified into a body consisting 
of a short stalk [filament) sup- 
porting two pollen sacs (the an- 
ther). The pollen grains are developed from mother-cells, 
each of the latter giving rise to four grains. The pollen- 
mother-cells themselves arise from the interior parenchyma 
of the stamen by the differentiation and enlargement of cer- 



Fig. 281.—^, a male flower oi Ahief^ iwcflnn- 
ta ; t>, bracts ; a, stamen s. B. pollen grain ; /», 
extine, with its large vesicular proa-usions, 
bl ; ^, intine ; y, celTin the inteiior of the pel- _ 

len grain developing tlie pollen tube: g, basal ±. fl^^^p^a 
cell attaching ?/ to the wall of the grain, x 300 cnt noweite. 
—A after Sachs ; B after Schacht. 




Fig. 282.— A catkin or spike of the 
male flowers cf Pinvs sylvestris. — 
From Le Maout and Decaisne. 



QYMNOSPERM^. 



395 





Fig. 283. — A sta- 
men from the flower 
and ^^ Pinus sylvesl/ris, 
showing the two pol- 
len sacs. Magnified. 
From Le Maout and 



tain cells. Each pollen grain is at first a single cell, but by 
the time it escapes from the anther it is a several-celled body, 
by the formation of partitions within its cav- 
ity {q, y, Fig. 281, B). The daughter-cells 
thus formed are doubtless the homologues of 
the prothallium of the higher Pteridophytes. 
Each mature grain has a double wall, of 
which the outer one (the extine) is hard 

and thick, while 

the inner one (^?^- 

tine) is thin 

delicate {e and i 

Fig. 281, B). In DecalsTi; 

this case (as indeed is common) 
there are two vesicular jorotru- 
sions of the extine {bl. Fig. 281, 
B), which give the grain the ap- 
pearance externally of being three- 
celled. 

The male flowers of Pinus syl- 
vestris are collected into catkins 
or spikes (Fig. 282). They are 
to those de- 
scribed above. The stamens are 
short and broad, and each bears on 
its back or outer surface two elon- 
gated pollen sacs (Fig. 283). The 



Pig. 284, — .4, male flower of 
Taxus baeeata; a, the pollen structurally similar 
sacs. B, a stamen, seen from '' 

helow. C, a piece of a foliage- 
ehoot, s, with a leaf, b, in whose 
axil is a scaly axis (the fe- 
male flower), which is terminated 
by an ovule, sk ; s, the scales. 
Z>, longitudinal section of the fe- 
male flower in C, moremagnifled; 

k!Thfrdy'„r°"Su?L°us"°o'nhi V^Wen grains are similar to those 

ovule; m, aril ; a?, a rudimentary q£ j4.bi6S 

axillary ovule. (I^^" By an error 

of the engraver the hairline from In TaXUS taccata the male floWCr 

cc IS carried about 1 mm. too high -i n i 

in the figure.) E. longitudinal diiiers irom tliosc described above 

section of an older ovule, but i • j i i p ±^ 

before fertilization ; ^, integu- OUly in the shapC 01 the StamCllS, 

rp«mTci^?wi,''%r»t,;g'''?h°; which are peltate and lobed (Pig. 
c?"Si*„t-,r(SS';h""fr:;; 384, B). They bear attached to 
'^"S^Tli^Si^ the under surface three to eight 
pollen-sacs, which contain many 
globose pollen grains. 
These examples will serve to illustrate the general struc- 
ture of the male flower, which, with minor variations, 



aril between the upper i-cale 
leaves and the ovule. All the 
figures magnified.— After Sachs 



396 



BOTANY. 



is ill nearly all "the class essentially like the ones described. 
The exceptions, which are in the order Grnetacese, will be de- 
scribed further on. It may be j)ointed out here that in jmss- 
ing up through the three orders of the class, the pollen sacs, 
which in the first resemble sporangia, become more nearly 
like the anthers of the Monocotyledons and Dicotyledons. 




Fig. 285. 



Fig 286. 



Fig. 287. 



Fig. 285.— J., pollen griiins of Biota orientalis before their escape from the pollen 
sac; I., fresh; //. and ///., after lying in water, the exiiiic, e, having been stripped 
off by the swelling of the intine, i ,• the protoplasmic contents are seen to consist 
of two cells, a large nucleated one, and a smaller one. B, pollen grain's of Finns 
pinaster, before their escape from the pollen sac ; e, extine, with its vesicnlar protru- 
sions, bl ; IV., side view ; V.. dorsal view — the protoplasmic content> are divided 
similarly to those in A. Magnified.— After Sachs. 

_ Fii^. 286.— J., a pollen grain of Chipressus sempervirens, showing the envelopes (ex- 
tine and intine), and the rudimentary prothallium as a small cell cut oti from tue 
cell contents. B, a germinating pollen grain ; e, the fragments of the ruptured and 
exfoliated extine ; ^, intine ; tp, the base of the pollen tube. X 400.— After Schacht. 
Fig. 287. — Pollen grains of Ceratozamia longifolia. A, before germination ; y, 
a three-celled body, the rudimentary prothallium. B, a germinating pollen grain ; e, 
the ruptured extine; ;w, the pollen tube; y, rudimentary prothallium. iMagnified. 
— After Juranyi. 



508. — The pollen grains, like the male flowers themselves, 
are essentially alike, although differing considerably in ex- 
ternal appearance. The vesicular protrusions of the ex- 
tine {U, Figs. 285, B, and 281, B), which are common in 
certain genera of the order Conifer m, at first sight hide the 
close similarity which exists between the pollen grains ia 
many cases. (Compare A, I., in Fig. 285, with B, IV. of the 



O7MN08PERM^. 



397 



same figure.) In all cases, unless possibly tlie Gnetaceae fur- 
nish some exceptions, the pollen grains become more than one* 
celled before the formation of the pollen tube (Figs. 281-5- 
0-7). When the pollen grains germinate — i.e., send out their 
tubes — they always swell up and 
burst the extine (which slips off 
in the ConiferGe), and the intine 
is then prolonged into a tube, 
which is continuous with the 
cayity of the grain, and into 
which the protoplasmic con- 
tents pass (Figs. 286 and 287). 
The small cells take no active 
part in the formation of the 
tube, and from their similarity, 
both in structure and function, 
to the small cells in the germi- 
nating microspores of the Sel- 
aginellw, there can be no doubt 
that they are to be regarded 
as constituting a rudimentary 
j^rothallium. 

509. — The female flower is 
in most cases a similar elon- 
gated axis, upon which are ar- 
ranged spirally a considerable 
number of phyllomes, each 
bearing two or more naked ov- 
ules. Thus in AMes pectinata 
the female flower is the young Fig. sss.-a. a bract, c, detached 

1 • T -J. J? • from Uieaxis of a youHg cone oi Abies 

cone, which consists 0± an axis pecUnata, with the scale, s, bearing the 

(^n V\a- 988 J^\ hp^ivina- -nnv ovules, sA;(enl^irged). iy, upper part of 

\SPf J^lg. ^00, J3) Dealing nai- a mature cone ; si», axis ; c. bracts ; s, 

row bracts {c), which, in turn, Sfoa'^thtfp'perSa.^TiSSce'd',': 
develop thick scales (s, s) upon g/'^^f ;; Vvt^g'Trea^ielf-lte; 
their upper surface. The scales Schacht. 

nre at first quite small (as in A), and it is only as the cone 
becomes older that they grow larger. Each scale bears on 
its inner face two inverted ovules {sh, Fig. 288, A). 

In Pi7ms sylvestris the structure is essentially the same as 




398 



BOTANY. 




Fig. 292. 



Fig. 293. 



Fig. 289.— A ripe cone (female flower) of Pinus sylvesfris. 

Fig. 290. —Partial section of a cone, sq, sg\ the ecales ; g, the seeds; em, the 
embryo in the seed. 

Fig. 291.— A detached scale of a ripe cone, seen from above, 'bearing two seeds. 
M, micropyle ; ch, chalaza. 

Fig. 292.— A detached scale of a young cone, seen from the back, showing the tri- 
angular bract. Magnified. 

Fig. 293— The same as Fig. 291, seen from the front, showing the two ovules. 
Magnified. 



O YMNOSPERMv^. 



399 




Fig. 294.— Female flower of Calli- 
tris quadrivalvis. d, d, decussating 
carpellary leaves ; Ks, six ovules. 
Magnified.— After Sachs. 



in the foregoing. The bract is smaller, however, and the 
scale attached to it soon becomes very large, thick, and 
woody (Figs. 289, 290, and 291). The bract and scale in 
this case have nearly the same relative proportions when 
young as they have in the mature 
cone of Alies pectinata. (Com- 
pare Fig. 288 with Figs. 292-3.) 
In other cases, as in CalUtris 
quadrivalvis, the axis is short, 
and the phyllomes {d, Fig. 294) 
which bear the ovules are only 
four in number (Fig. 294, Ks, 
the ovules). In Taxus haccata 
the flower is still more simple. 
It appears in the axil of a foliage 
leaf, and is a scaly axis, resembling a small cone {C, Fig. 
284). The lower scales do not, however, bear ovules, and 
at the top of the axis is a single naked ovule (D and E, Fig. 
284). This simplicity is carried a step further in Ginhgo, 
where the female flowers are merely naked axes, which bear 

no bracts or scales, 
and produce but two 
ovules at their sum- 
mits (Fig. 295, slc)^ 
The female flower 
of Cycas revoluta is 
a rosette of phyl- 
lomes, which bear 
some resemblance to 
foliage leaves, being, 
however, smaller. 

Fig. 295.— A shoot of Ginkgo hiloba. sJc. ovules brownish, and hairy, 
in pairs at the ends of naked axes ; above and on the A ] p.,, ^v. -fUp 1 n w a v 
right are shown fragments of two leaves, which xxiuiig Liie i u w e i 
are seen to be broad. Nat, size. -After Sachs. narts of their mar- 

gins they produce a number of spherical naked ovules {sk, 

* The morphology of the flowers of Ginkgo, as here oriven, is by no 
means satisfactory. Instead of the ovules being borne upon naked 
axes, it is probable that they are in reality upon foliar organs— ^.e., 
either modified leaves, somewhat as in Cyca-, or upon elongated homo- 




400 



BOTANY. 



Fig. 296). These stmctnres, which may be called carpel- 
lary leaves, show their relationship to ordinary foliage leaves 









- f- Ml 



:<?:. 






^^ 
















Pig, 296.— A pinnate, open carpellary leaf of Cycas rewluta (reduced one half). /, 
nnaltered pinnae ; sic, young ovules replacing the lower pinnse; sk', fully developed 
ovule. — After Sachs. 

in having pinnaB toward their summits (/, Fig. 296). 

The examples given will illustrate the general structure of 

loi^ues of the " scales " of Abies. Either interpretation would necessi- 
tate a considerable change in the systematic arrangement of TaxinecR. 



G YMNOSPEBMy^. 



401 



the female flower of the Gymuospcrms. The only consider- 
able departure from the plan of the flower, as here given, is 
found in the order Gnetacece^ which will be described further 



on. 



510. — The ovule is at first a mmute protuberance of 




em 



Fig. 297.-4, longitudinal section of an ovule of Pinus Larico, taken from a 
cone just opened ; c, the coat of the ovule, in section ; ov, the body or "nucleus" of 
the ovule ; this includes all the figure which is filled out, showing the cells ; em, the 
young embryo sac. B, a similar section of the ovule of Abies peciinata^ after the en- 
trance of the pollen tube;^, 2ji, into the corpuscula, cp, cp ; ov, the body or " nucleus"' 
of the ovule— the upper portion is cut away (the cells composing its tissue are not 
shown); w, the wall of the embryo sac; en, endosperm in the enlarged embryo sac ; 
cp, cp, two corpuscula ; n, the neck of one of the corpuscula ; /??% the first cells of 
the pro-embryo. A X 150 ; B x 30.— J. after Hofmeister ; B after Strasburger. 



small-celled tissue ; a little later a ring grows out from its 
base, and rises as a sheath (the integume^it or coat), which 
finally more or less completely closes it in ; in a few cases a 
second integument forms outside of the first one. At a cer- 
tain stage of its growth one of the interior cells of the ovule 
grows larger than the others, and becomes the embryo sac 
[em, Fig. 297, A) ) in it there arise numbers of free cells, 



402 



BOTANY. 



wliich multiply by fission, and eventually unite into a con- 
tinuous tissue (in reality a false tissue), the endosperm {en, 
Fig. 297, B). In this mass of endosperm cells several near 
the micropylar end grow larger than the surrounding ones, 
and become filled with granular protoplasm. These are the 

corpuscula of Brown, the 
arcliegonia of Sachs, or 
the secondary embryo sacs 
of Henfrey [cp, cp, Fig. 
297, B). In some cases 
they are placed singly at 
short distances from each 
other, while in others they 
are clustered together 
(1 and 2, Fig. 298). Each 
corpusculum is at first a 
single cell, but when fully 
developed it consists of an 
elongated cell, the germ- 
cell proper, and, in many 
cases at least, one or more 
neck-cells, the whole sunk- 
en deeply into the sub- 
Fig. 298—1. Three corpnecula. cp, of Juni- staUCC of the Cndospcrm. 
penis communis, close together, and seen in a ,-p,, ^ • d -\ i n 

longitudinal section of the ovule ; ei, the first 1 hC nCCK IS lOrmed by the 
suspeneor cells of two fertilized corpuscula — , , • «> ^ i.- _e 

at the upper end of the corpuscula are chown Cutting Ott 01 a portion 01 
the neck cells ; p, the lower end of the pollen ;-| nvio-inal n^ll nf ihc^ nr>v 
tuhe. 2. A similar section taken a little later ; tUC Ollgmal Celi 01 tnc COr- 
v,v,the suspensors, or pro-emhryos ; e, e, e, ^^iTooi^him • in qatyip pricspq 
cells of the endosperm. 3. Lower end of sus- PUSCUiUm , in SOme CaSCS 
pensor, with enibryo. ^6, begiiining to develop, it remains sinde, whilc in 
4, Longitudinal section ol the body or "nu- . . . 

cleus," &A:, of the ovule, shown in outline; e, othcrS it dividcS SO aS to 
endosperm in enlarged embryo sac ; ^^ portion „ j_- i ^ 

of endosperm broken up: cp. three corpus- lOmi a VCrtlCal rOW, and 
cula, from the lower ends of which the suspen- • ,^ » 

sors, V, grow ; j), pollen tube. 1 and 2 X 200 ; m OtnCrS a lOUr- Or CVCn 
3 X 100 ; 4 X 50.-After Hofmeister ^-^j^^ _ ^^^j^^ traUSVCrSC 

plane (see Fig. 298, 1) ; the latter arrangement has been 
termed a rosette. 

511. — If we now review the structure of the ovule its ho- 
mologies can be readily made out. The ovule itself plainly 
corresponds to the macrosporangium of the higher Pterido- 
phytes, and the embryo sac is to be regarded as the homo- 




G YMNOSPEBMM. 



403 



jogue of a macrospore, whicli liere is not freed from tlie 
parent plant. The endosperm clearly bears the same rela- 
tion to the embryo sac as the prothallium of Isoetes does to 
the macrospore ; and the corpuscula are slightly modified 
archegonia. In some corpuscula the resemblance to arche- 
gonia is very marked, the germ-cell below being surmounted 
by a short neck ; Strasburger has even discovered a rudi- 
mentary axial-cell, thus completing the correspondence of 
these organs to those of the 
higher Pteridophytes. 

512. — Fertilization is effect- 
ed by means of the pollen, 
which comes in contact with 
the apex of the ovule. It is 
transported from the male 
flowers mostly by the wind, 
which accounts for the im- 
mense quantity p r o d u c e d . 
When the ovule has reached the 
proper stage the micropyle is 
filled with a fluid, which, dry- 
ing, carries the adherertt pollen 
grains into contact with the 
apex of the ovule body, where 
they germinate and form pol- 
len tubes ; the latter penetrate 
the soft tissue of the ovule and 
eventually reach the corpus- 
cula (Fig. 299). In those cases where the corpuscula are 
separated from one another each pollen tube comes in con- 
tact with only one corpusculum (Figs. 297, B, and 299) ; but 
when the corpuscula are close together a single pollen tube 
may come in contact with all of them (Fig. 298, 1 and 2). 
The union of the protoplasm of the pollen tube with that of 
the germ-cell appears to take place by diffusion through the 
wall of the former, as no openings in it have been discovered. 
After fertilization the protoplasm in the germ-cell becomes 
more turbid and granular, and soon at the base a transverse 
partition is formed, cutting off a cell, which is the rudiment 




Fig. 299. — Diagrammatic section of 
an ovnle of Piniis, showing fertiliza- 
tion, i, integument or coat of tlie 
ovuie ; OT, the micropyle ; k, the body 
or " nucleus" of the ovule ; e, the em- 
bryo sac, filled with endosperm ; c, c, 
two corpuscula shown filled with pro- 
toplasm ; A, the neck cell of one cor- 
pusculum ; p. two pollen grains ap- 
plied to the apex of ihe ovule body, 
into which they have sent two pollen 
tubes, s, s. — After Prantl. 



404 BOTANY. 

of the suspensor. By the growth and fission of this first 
cell an elongated tortuous filament — the suspensor — is at 
leugtli formed, wliich develops at its lower extremity a rudi- 
mentary embryo {eb, Fig. 298, 3). Sometimes each suspen- 
sor sj^lits into several parallel ones, each of which forms a 
rudimentary embryo, but in such cases it rarely happens 
that more than one continues to grow. While the embryo 
is growing the ovule increases greatly in size, and its coat 
becomes hardened or otherwise modified. Internally, the 
endosperm in the embryo sac grows still more rapidly, and 
finally entirely replaces the other tissues of the ovule. The 
endosperm-cells at this stage are filled with nutrient materials 
for the support of the embryo. 

513. — The stem of the embryo develops upon the lower 
end of the suspensor as a very short cylindrical mass ; the 
end opposite to the suspensor is a growing point {punctu7}i 
vegetationis), and this produces two or more cotyledons as 
lateral members ; lastly, upon the end of the axis next to, 
and under, the suspensor a rudimentary root forms, coyered 
with a few-celled root- cap. The fully formed embryo has 
thus, (1) an axis (called also the hypocotyledonary stem, c"au- 
licle, and erroneously the radicle) ; (2) the cotyledons ; (3) a 
growing point above the whorl of cotyledons (called also the 
plumule) ; (4) a rudimentary root, which is the true radicle, 
and to w^hich alone the term should be applied. 

514. — When the ovule and its contained embryo reach the 
stage last described above they constitute the Seed. The 
growth of the embryo is suspended, and the tissues which 
maintained organic connection betw^een the ovule and the 
parent plant are absorbed, thus setting the seed free. Under 
proper conditions the suspension of the growth of the em- 
bryo may be prolonged for some years without the loss of 
its power of resuming it again ; this latter, or the germina- 
tion of the seed, takes place wdienever the necessary amounts 
of heat and moisture are present. The first stage in germina- 
tion is the swelling of the endosperm, which ruptures the 
hardened integument (testa) ; this is followed by the rapid 
elongation of the axis (caulicle) of the embryo, by which the 
growing root is pushed out (Fig. 300, //.) ; the latter forms 



G YMNOSPERM^. 



405 



the first root of the 
its whole root sys- 
tem. The cotyle- 
dons haying thus 
far been in contact 
with the e n d - 
sperm, which fur- 
nished them with 
nourishment, now 
elongate and push 
out their bases, and 
in some cases even- 
tually withdraw 
themselves entirely 
from the seed coat 
(Fig. 300, ///.). 
The apex of the 
axis (plumule) be- 
gins a rapid growth, 
which gives rise to 
a leafy stem resem- 
bling that of the 
parent 2:)lant, al- 
though usually 
somewhat sim]3ler. 

515.— The tis- 
sues of the Gymno- 
sperms are individ- 
ually but little high- 
er than those of the 
Pteridophytes, but 
in the mode of their 
aggregation they 
present great and 
important differ- 
ences, in this latter 
respect bearing a 
close resemblance to 
the tissues of the 
Dicotyledons among 



new plant, and eventually gives rise to 




Fig. 300.— Seeds of Finus Piiiea in different stages of 
germination. /., ripe seed in lonp-itndinal section; «, 
the seed coat ; e, endosperm ; w, tne hypocotyledonary 
axis of embryo ; c, cotyledons ; y. the micropylar end 
of the seed, with the root of the embryo directed to- 
wards it. 7/., //., four views of the beginning of ger- 
mination ; A, external view ; B. with half of the seed 
coat removed ; C, in longitudinal section ; D, in 
transverse section ; .*, seed coat ; 1\ red membrane lin- 
ing the seed coat ; <?. endosperm ; c, cotyledons ; w, 
root ; a;, ruptured embryo sac. ///., germination com- 
plet<i, the cotyledons, c, unfolding, and the hypoctyle- 
donary stem. ?ic, elongating ; w, the main root, devel- 
oping lateral roots, iv'.—MiQr Sachs. 

the Angiosperms. The three tissue sys- 



40G 



BOTANY. 



terns are well defined, and include most of the tissues de- 
scribed in Chapter VI. (page G9 et seq.). 

The epidermal system consists of one or more layers of 
epidermal cells, which are frequently much thickened; 




Fig. 301.— Diagrammatic cross-sections of the. stem of Gymnosperms. A, young 
stem with the fibro-vascular bundles, fb, widely separated ; p, the phloem ; x, the 
xylem ; fs, tissues of the fundamental'system ; e, epidermis. Z?, a similar section of 
an older sttr'm, the cambium layer, c, extended through the fundamental system 
from bundle to bundle. C, section of a three-year-old stem, showing the manner of 
increase in the xylem and phloem ; pc, primary cortex (phloem) ; sc, secondary cor- 
tex (phloem) ; c, cambium layer ; sw, secondary wood (xylem) ; pw, primary wood 
(xylem) ; p, pith ; 2?1, p2, jo3, ccl, cc2, ceS, corresponding phloem and xylem portions 
of each year's growth of the bundle. 

stomata are common, and in general, are quite regularly dis- 
posed in lines ; the outer surface is occasionally covered with 
well-developed trichomes ; in general, however, they present 
themselves as rough points, which give a harshness to the 



G TMN08PERMJE. 



407 



surface. In many cases oil or resin receptacles occur in, or 
immediately beneath, the epidermis. 

516. — The fibro- vascular bundles are for the most part 
of the collateral form, and in the young stem they are ar- 
ranged so as to form an inner xylem cylinder ensheathed by 
a phloem cylinder (Fig. 301). The xylem of these first- 
formed bundles is composed of an inner mass of annular and 
spiral vessels, which gradually pass outwardly into tracheides. 
The phloem is mostly composed of an outer mass of bast 




Fig. Wla.— Cross-section thro^sh the new wood (Ji-h), cambium (x-x), and bark 
(Jb-b) of the stem of JindpevKS comminns, made at the end of September, m, m, me- 
dullary rays. In the bark are shown the layers of bast fibres, b, b, b. Magnified.— 
After De Bary. 

fibres, which is bordered internally by a mass of sieve tissue 
(latticed or cambiform cells) and parenchyma. Between the 
xylem and the phloem a layer of cells always remains as a 
meristem tissue ; this constitutes the cambium layer of the 
bundles (c. Fig. 301, B., and X-X, Fig. 301«). 

517. — The increase in the diameter of the stem takes 
place by the multiplication of cells in the cambium layer ; 
the cambium cells undergo longitudinal fission by the forma- 
tion of partitions at right angles to the radii ; these new cells 



40S BOTAXY. 

are developed on tlie one hand into traclieides, wliicli com- 
pose the secondary Avood, and on the other into parenchyma 
and fibrous tissue, composing the secondary cortex {sio and 
sc, Fig. 301, C). There always remains a layer of meristem 
tissue between the secondary wood and cortex thus formed, 
so that the next year an additional increase is made again in 
exactly the same manner. Thus it happens that the new 
gi'owtli takes place between the xylem and j^hloem portions 
last formed, and that the corresponding xylem and phloem 
parts of any year's grow^th come at last to be separated by 
the similar parts of all the subsequent years' growths {fb, 
Tig. 301, C). 

The tracheides are much elongated, w4th somewhat taper- 
ing ends ; their walls are tliickened, and are more or less 
coiDiously sujDplied with bordered pits. (See Fig. 15, p. 25.) 

518. — The fundamental system of tissues in the stem be- 
comes divided into two portions by the development of the 
fibro-vascular cylinder described above. The inner j^ortion, 
the pith, which occupies the axis of the stem, is composed of 
parenchyma, which soon loses its vitality, and persists as a 
mass of thin-walled and generally empty cells. The outer 
portion, the primary cortex, consists of parenchyma, which 
is usually chlorophyll-bearing, and a greater or less amounL 
of sclerenchyma or coUenchyma. There is frequently a con- 
siderable development of cork in the primary cortex, and 
not rarely the whole of the jirimary cortex nndergoes a 
corky degeneration. Between the fibro-vascular bundles 
there are broader or narrower plates of tissue, composing the 
so-called medullary rays, which in the young stems are 
parenchymatous, but in older ones they are sclerenchyma- 
tous (Fig. 301^, m, m). In that portion of each medullary 
ray lying between the cambium layers of two contiguous 
fibro-yascular bundles there is a layer of meristem tissue, the 
cambium of the medullary rays, or the inter-fascicular cam- 
bium. As this is continuous with the cambium of the 
bundles, there is thus formed a cylinder of cambium, sepa- 
rating not only the fibro-vascular, but also the fundamental 
portions of the stem, into two parts {B, Fig. 301). By the 
formation of new cells by fission in the inter-fascicular cam- 



G TMyOSPEBM^. 4C9 

bium at the time of activity in the cambium of the fibro- 
yascuhir bundles, there is an annual addition made to the 
fundamental tissues of the stem corresponding to the addi- 
tion made in the fibro-vascular bundles. 

519. — By this internal increase of tissues in the stem the 
epidermis is at length ruptured, and the primary cortex be- 
comes exposed, and eventually broken up and destroyed. 
The phloem portions of the fibro-vascular bundles, and the 
subsequent external additions to the fundamental tissues 
made by the inter-fascicular cambium, constitute what is 
called the Bark of the stem. There are usually in it corky 
developments, which often very considerably change the 
character and alter the relations of its parts. The paren- 
chyma f recpiently becomes somewhat sclerenchymatous, while 
in other cases it undergoes a peculiar degeneration. 

520. — Most Gymnosperms have intercellular canals in 
their stems, either in the fibro-vascular or the fundamental 
portions ; these contain a turpentine in which is dissolved a 
resin.* 

521. — There are three quite well-marked orders of Gym- 
nosjoerms, which may be separated as follows : 

1. Cycadese, the Cycads. Stem simple, or rarely branched, 
not resinous ; pith large ; leaves large, pinnately compound, 
crowded upon the stem. 

2. Coniferse, the Conifers. Stem branched, usually resin- 



* Tlie distribution of tliese canals lias been made out by Van Tiegliem 
{Ann. des Sci. Nat., 1872) to be as follows for the principal genera of 
Coniferce : 

1. No canals in root or stem — Taxus. 

2. Canals in the stem only. 

{a) In the cortical parenchyma — Taxodium, Podocarpus, Tor- 

reya, Tsuga, etc. 
(&) In the pith also — Ginkgo. 

3. Canals in both stem and root. 

In the cortical parenchyma of the stem — Gedrus, Abies, etc. 

(a) In the xylem of the fibro-vascular bundles of root and 

stem — Pinus, Larix, Picea, Pseudolarix. 
(&) In the phloem of the fibro-vascular bundles of root and 

stem — Tliuya, Cuprcssiis, Biota, Araucaria, etc. 



410 BOTANY. 

ous ; pith slender ; leaves small, simple, mostly crowded 
upon the stem, sometimes scattered. 

3. Gnetaceae, the Joint-Firs. Stem branched, not resin- 
ous ; pith slender ; leaves small, opposite, upon elongated 
internodes, or large and only two on a short, thick stem. 

Order Cycadese. — The Cycads are large or small trees, with much 
the general appearance of the palms and tree-ferns. They are of slow- 
growth and are long-lived ; the stem elongates by a slowly unfolding- 
terminal bud, which gives rise to a crown of widely-spreading pinnate 
leaves, which are constantly renewed above as they die and fall away 
below. 

'Nine genersi (Gycas, EncepJialartos, Macrozamia, Zamia, Ceratozamia, 
etc.), and from fifty to sixty species, are known ; they are all tropical or 
sub-tropical, and are about equally distributed in both the Eastern and 
Western continents. Three species occur within the United States (in 
Florida), viz., Zamia irUegrifoliii , Z. jpumila, Z. Floridana. 

Many species contain considerable quantities of starch in their thick 
stems ; from this a kind of sago is made. In some cases the seeds also 
are nutritious. 

Order Coniferae. — The Conifers are for the most part trees of a con- 
siderable size, v/ith branching, spreading, or spiry tops. They are 
generally of rapid growth, and in many cases attain a great height and 
diameter. In the greater number of species the leaves are persistent^ 
and the trees, consequently, evergreen. 

The order contains thirty-three genera and about three hundred spe- 
cies, which are distributed mainly in the cooler climates of the globe. 
Fifty or more species occur within the limits of the United States. 

The disposition of the genera may be understood from the following 
arrangement, which is essentially that of Parlatore in De Candolle's 
" Prodromus" : 

Tribe I, Tciocinece. — Flowers dioecious or rarely monoecious ; 
fruit fleshy ; non-resinous trees or shrubs. 

Gen, Ginkgo (Salisburia), Phyllocladus, Podocarpus, Torreya, Taxus, 
etc. 

The seeds of Ginkgo are eaten in Japan as a dessert. Many species 
furnish valuable timber, which is generally very durable. The wood 
of the jew {Taxus baccata) of Europe and Asia is almost indestructible. 

Species of Podocarpus in Java, Australia, and New Zealand attain a 
great height, and afford good timber ; allied species in the West Indies 
and South America are equally valuable. 

Ginkgo is now planted in this country as an ornamental tree. 

Tribe II, AJbietiiiece, — Flowers monoecious or dioecious ; fruit a 
woody cone (excepting in Juniperus). Resinous trees, a few shrubs. 



CONIFERS. 411 

Sub-Tribe I. Cupressece. — Scales of tlie cone four or more, decus> 
satelj opposite, or tliree or four in a whorl, persistent. Leaves usu- 
ally scale-like, persistent, opposite or wliorled. 

Gen. Jumper us, Cupressus, Gliamcecyparis, Thuya, Libocedrus, Calli- 
tris, etc. 

The fleshy cones (the so-called berries) of Juniperus commurds are 
used in medicine, as are also the leaves of J. Sabina ; from the former 
an oil is obtained by distillation. 

The wood of most of the species is valuable. 

From Juniperus Virginiana of North America and J. Bermudiana 
of the Bermudas, the wood is obtained for making lead pencils. 

Cupressus sempervirens is the Cypress, a native of the Levant ; its 
wood is nearly indestructible. 0. macrocarpa is the beautiful "Mon- 
terey Cypress " of California. 

GhamcBcyparis sphoeroidea, the White Cedar of the Eastern United 
States, is used in the manufacture of pails, tubs, etc. Several allied 
species from Japan are cultivated under the name of Retinospora. 

Thuya occidentalis, the Arbor Vitse of the Eastern United States, sup- 
plies enduring posts, etc. ; its congener of California and Oregon {T. 
gigantea) is an immense tree 30 to 60 metres (100-200 ft.) high. 

Libocedrus decurrens, nearly related to the last named, is another 
large Californian tree. 

Bub-Tribe II. Taxodiece. — Scales of the cone spirally arranged 
(wliorled in one genus), persistent. Seeds three to nine upon each 
scale. Leaves usually linear, arranged spirally, or in two ranks. 

Gen. Taxodium, Sequoia^ Sciadopytis, etc. Taxodiurn distichum, the 
Bald Cypress of the Southern United States, is valuable for its durable 
timber. S.quoia gigantea, the Giant Redwood, or Big Tree of Califor- 
nia, grows only on the western slo[;es of the Sierra Nevada Mountains. 
It attains a height of more than 100 metres (300 ft.), and a diameter of 
6-10 metres (20 to 30 ft.). Its wood is red in color, and very durable. 8. 
sempermrens, the Redwood of the Coast Range Mountains, is a some- 
what smaller tree ; its durable timber is much used for making shingles, 
weather-boarding, fences, etc. Sciadopytis verticillata imd Gryp'omeria 
Japoiiica, large trees of China and Japan, furnish valuable timber. 
They are now considerably grown in the United States. 

Sub-Tribe III. Pinece. — Scales of the cone spirally arranged, usually 
persistent. Seeds two upon each scale. Leaves linear (or, in some cases, 
scale-like on the primary shoots), spirally arranged. 

Gen. Tsuga, Abies, Picea, Larix, Pinus, etc. Tsuga Ganadensis, the 
Hemlock-Spruce of the Eastern United States, and T. Douglasii {Pseu- 
dotsuga Douglasii of Carriere), the Douglas Spruce of Oregon and Cal- 
ifornia, are valuable timber trees. The former attains a height of 30 
metres (100 ft.), and the latter of nearly 100 metres (300 ft.). Both are 
valuable for making the frames of houses and ships. 



4VZ BOTANY. 

The genuR AHes contains tlie Balsam Fir, A. halmmea, of Eastern 
United States, tbe Silver Fir of Europe, A. pectinata, the Giant Silver 
Fir, A. grandis, of Oregon and Calilornia, besides many others. All 
furnish valuable timber, and from the first is obtained a fine turpentine 
known as Canada Balsam. 

Plcea excelsa, the Norway Spruce of Northern Europe, is a large tree 
80 to 50 metres (100-150 ft.) high, from which white deal timber is ob- 
tained ; from its turpentine Burgundy pitch is made. P. nlha, the 
White Spruce of Canada, and P. SitchensiH and P. prmgens of the 
Western United States, are valuable lor timber, and are planted for 
ornamental purposes. 

Larix Ainericana, the Tamarack or American Larch of Eastern 
North America, and L. Europcea, the Larch of the mountains of Cen- 
tral Europe, are valuable timber trees ; from the latter Venice turpen- 
tine is o])lained. 

The genus Pinus contains many important trees ; they may be 
grouped as follows : 
{a) Leaves in fives. 

P. Strohus, the White Pine of Eastern North America ; this is our 
most valuable species, as it furnishes the greater part of the pine 
"lumber" used in the Northern States ; it often attains a height of 
60-60 metres (160-200 ft.). 

P. Lambertiana, the Sugar Pine of California, is like the preceding, 
but of greater size, being from 60 to 90 metres high (200-300 ft.). 
{b) Leaves in threes. 

P. au4ralis, the Yellow Pine of the Southern United States, fur- 
nishes a durable timber, used for flooring, shipbuilding, etc. Its tur- 
pentine, which is obtained by cutting into the trees, yields spirits of 
turpentine by distillation ; the residue is rosin. Tar is obtained by 
slowly burning the wood in kilns ; and by evaporating the volatile 
matters from tar, pitch is produced. 

P. 'ponderosa^ the Yellow Pine of the Eocky Mountains and California, 
is similar to the former, but of greater size, being 30-100 metres high 
(100-GOO ft.). 

(c) Leaves in twos. 

P. sylvestris, the "' Scotch Fir," or " Scotch Pine," is a native of 
Northern Europe and Asia. Its timber is extensively used in England 
under the names of Dantzic Fir and Riga Fir, in the building of ships, 
docks, houses, etc. 

P. laricio is a less valuable tree of Southern Europe ; it is known in 
this country as Austrian Pine, and, with the preceding, is commonly 
planted with us for ornamental purposes. 

P. resinosa, the Red Pine of Canada, is a tall and slender tree, much 
used for making masts and spars. 
{d) Leaves single. 
P. monophyllos, the Nut Pine of the Utah-Arizona district, is pecu- 



(jtNETACEJE:. 413 

liar in its single leaves. Its seeds are large and constitute an impor- 
tant article of food for the Indians. 

Sub- Tribe IV. Araucariejp. — Scales of tlie cone spirally arranged, 
deciduous. Leaves flat or four-angled, often broad, sub-opposite, or 
spirally arranged. 

Gen. Dammar a, Araucaria. Dammar a australis is tlie Kauri Pine 
of New Zealand, wliicli attains a height of 60 metres (200 ft), and is 
much used for making masts. From D. alba of the Malay Islands 
Dammar resin is obtained. 

The genus Araucaria contains large pyramidal trees of singular 
beauty. A. excelsa, the Norfolk Island Pine of tlie South Pacific Ocean, 
is 45 to 60 metres high (150-200 ft.),with horizontal verticillate branches, 
forming a pyramidal head. The timber is valuable. This species 
and A. imbricata froni Chili, and A. Bidwilli, of Australia, are now 
grown for ornamental purposes in California. 

Order Gnetaceee. — The Joint-firs are undershrubs, or small trees, 
with usually jointed rush-like stems, and opposite setaceous or oval 
leaves (the exceptional WehoitscJiia will be described below). The 
flowers differ from those of the other Gymnosperms in always having a 
perianth — i.e., a floral envelope ; in some cases this is single and bifid, 
while in others it is composed of two or more bract-like bodies (phyl- 
lomes). The stamens are single (in Gnetum), or six to eight united 
into a tube or column. The ovules are single in each flower, and are 
provided with one or two envelopes ;* in the former case the single 
integument, and, in the latter, the inner one, is prolonged beyond the 
body of the ovule into a style-like process, which is occasionally ex- 
panded above into a stigma-like body. 

The flowers are disposed in the axils of the opposite bracts of short 
lateral branches (aments or catkins), which spring from the axils of 
the leaves upon the main stems. 

Three genera of Gnetacese have been described, viz. : (1) Gnetum, 
with from fourteen to eighteen species, mostly confined to the East In- 
dian islands and the tropical portions of South America ; (2) Ephedra, 
with about as many species, widely distributed in temperate and trop- 
ical regions (five species occur in the southwestern part of the United 
States) ; (3) Welwitschia, with but one South African species. 

* In Gnetum Gnemon there are three envelopes surrounding the 
body of the ovule, but it is probable that the outer one is to be re- 
garded as belonging to the perianth. Some botanists reject the idea 
that any of these are proper ovule integuments, and regard the inner 
one as a true ovary, and the outer one or two as belonging to the peri- 
anth or staminal whorl. This is the position taken by Parlatore in 
De Candolle's " Prodromus ;" by Beccari, in " Nuovo Giornale Botan- 
ico Italiano," Jan., 1877 {Delia Organogenia, etc., del Gnetum Gnemon)\ 
and by Dr. Gray, in " Bot. Text-Book," 6th ed., 1879, vol. 1, p. 269. 



414 



BOTANY. 




GNETAGE^, 415 

The most remarkable member of the order is Welwits'-Ma mirabilis 
(Fig. 302) discovered by Dr. Welwitscli in 1860, and described by Dr. 
Hooker in 1862.* It consists of a short, thick, woody stem rising- 
30 cm. (1 ft.) above the ground, and having a diameter of from 30 to 
50 cm. (12 to 20 in.), and even attaining in some cases, according to the 
discoverer, a diameter of 1.4 metres (4|- it.). From the lower portion 
of this stem a stout tap-root passes downward, branching more or less 
at its lower end. The top of the stem is nearly flat, there being usu- 
ally a slight depression across its diameter. There are only two leaves 
attached to this curious stem, and from the study of the young plants 
it seems probable that they are the persistent cotyledons. They arise 
in two deep grooves in the circumference of the upper part of the stem, 
and as tbey continue to grow at their bases they eventually attain a 
great length, being nearly two metres long (6 ft.) in full grown plants. 
They are thick and leathery in texture, and their fibro-vascular bun- 
dles are all parallel and free from each other, running from the base of 
the leaf to its split and frayed apex. From the circumference of the 
stem, above and close to the bases of the leaves, spring stout branching 
peduncles, which bear clusters of scarlet cones (Figs. 302 and 303). 
These cones are composed of numerous opposite bracts arranged in 
four rows. In the axil of each bract there is a single flower, consist- 
ing in the male cones of a perianth of two pairs of decussating bracts 
enclosing a ring of partly united stamens ; within these is a rudimen- 
tary, abortive ovule, whose single coat is curiously prolonged so as to 
resemble a pistil with style and expanded stigma. In the flowers of 
the female cones the perianth is a compressed, winged tube, lying 
within the broad scales, There are no rudiments of stamens ; and in 
the centre of the perianth there is placed a single erect ovule with one 
elongated integument. 

It will thus be seen that the cones of WelwiUchia, while bearing 
some external resemblance to those of Coniferse, are not homologous 
with them ; inWelwitschia they are short, flower-bearing, bracted axes ; 
in Coniferse they are stamen-bearing or pistil-bearing axes, in other 
words, each cone is a multistaminate or multiovulate flower. 

Fossil Gymnosperms. — G}"mnosperms first appeared in the Devo- 
nian, in which they were represented by species of Prototaxis, Gladoxy- 
lon and ScMzoxylon, doubtfully referred by Schimperf to the Coniferse. 
True conifers were present in the Carboniferous, in the Permian they 
were abundant, and in the Tertiary exceedingly so. Araucaria was 
represented in the Jurassic by several species. Pinus, Abies, Gedrus 
and Sequoia originated during the Cretaceous period, and were repre- 

* " On Welwitschia, a new Genus of Gnetacese," by J. D. Hooker, 
in "Transactions of the Linnean Society," Vol. XXIV. 

f " Traite de Paleontologie Vegetale," par W. Ph. Schimper, Paris, 
1869-1874. 



41G BOTANY. 

sented by many species during the Tertiary. It is interesting to note 
that the present small and restricted genus Sequoia was during Cre- 
taceous and Tertiary times large and widely distributed throughout the 
northern hemisphere. In this country two Cretaceous species are re- 
corded from Nebraska and Kansas, and eight species from the Tertiary 
of Colorado, Utah, Montana, and the region westward. 

The Cycads originated in the Carboniferous, and increased in num- 
bers to the Jurassic, in which twenty or more genera were richly repre- 
sented in species. A Cretaceous species of Pterophyllum from Nebraska, 
and a tertiary Zamiostrobus from Colorado have been described. 

Two species of Ephedra from the Tertiary of Europe are the only 
known fossil Gnetacese. 

§ III. Class Angiosperm^. 

522. — This class includes the great mass of tlie so-called 
flowering plants. The principal characters which set these 
off from the preceding small class of the Phanerogams 
(Gymnospermse), are (1) the development of an oyary, and 
(2) the aggregation of the reproductive organs into a defi- 
nite and distinct flower. 

523. — The plants of this class have, in most cases, more 
or less elongated stems ; these are solid at first, and in the 
great majority of cases they remain so. They usually bear 
ample leaves with a parallel (in the Monocotyledons), or 
netted venation (in the Dicotyledons). The disposition of 
the fibro-vascular bundles in the stem is either like that in 
the Gymnosperms (in most Dicotyledons), or they run 
through the fundamental tissues parallel to, but independent 
of, one another (in most Monocotyledons). In the former 
case, the stems of the perennial species increase in diameter, 
m the same way that they do in Gymnosperms, and there is 
here also a well-marked division into pith, wood and bark ; 
in the latter case there is usually no increase in the diameter 
of the stem after it has elongated, and in tne few cases of 
considerable increase it takes place by methods very different 
from that described in the preceding class. 

Most Angiosperms are terrestrial and chlorophyll-bearing 
plants ; there are, however, many aquatic and aerial species, 
and a considerable number of parasites. They range, also, 
in size and duration, from minute annuals, a millimetre in 



ANQI08FEBMJE. 



41 r 



extent, to enormous trees, 50 to 100 metres high, and often 
several or many centuries old. 

524. —The flowers of the Angiosperms, while sometimes 
so reduced as to be quite simple, are in all cases much more 
complex than those of Gymnosperms. In most cases they 
are monoclinous (hermaphrodite), ?°.e., the male and female 
sexual organs occur in the same flower ; in such case each 
flower consists essentially of an axis bearing one or more 
pollen - producing organs 
{anthers, Fig. 304, a), and 
one or more ovule-contain- 
ing organs [ovaries, Fig. 
304, F). These are, when 
more than one, generally 
arranged upon the axis in 
one or more whorls ; the 
staminal whorls normally 
arise below the ovaries. Be- 
sides these essential organs, 
there are usually secondary 
or accessory organs, such as 
the delicate, and frequent- 
ly colored floral leaves {pet- 
als or sepals, K and Ke, 
Fig. 304), the honey glands, 
etc. 

525. — The axis of the 
flower (the Torus or Re- 
ceptacle), usually remains 
very short, so that the different organs of the flower are 
closely approximated, and thus distinctly set off from ' tlie 
other parts of the plant. The axis is, moreover, but v^ry 
rarely prolonged beyond the flower, all growth ceasing in it 
when the floral organs are developed. In most cases the re- 
ceptacle is conical or hemispherical in shape ; in other cases 
it develops into various shapes, the principal ones of which 
will be noticed hereafter. 

526. — The lower portion of the flower axis generally bears 
one or more whorls of modified leaves (phyllomes), which 




Fig. 304.— DiagrainTnatic section of an an- 
giospernious flower. Ke, calyx ; X, corolla ; 
/, the filament, and a the anther of the sta- 
men ; p, pollen grains, some in the anther, 
others on the stigma ; F, the ovary ; g, the 
style, and n the stiiima of the pistil— the 
ovary contains one ovule, which has a single 
coat, *, enclosing the ovnle body, S ; em, the 
embryo sac ; E, germ cell or germinal vesi- 
cle ; ps, a pollen-tube penetrating the style, 
and reaching the germ-cell through the mi- 
crupyle of the ovule.— After Prantl. 



I 



418 BOTANY. 

constitute the floral envelopes, or, technically, the perianth. 
Frequently there is a strong difference between the outer and 
inner whorls, and in such cases the former is distinguished 
as the calyx, and the latter as the corolla. 

527. — The whorl of stamens (technically the Andrcecium) 
develops above the upper whorl of the perianth. Each 
stamen generally consists of a slender, thread-like stalk (fila- 
ment), bearing upon its upper extremity from one to four 
pollen-sacs ; this pollen-containing portion, whether one or 
more celled, is known as tlie anther. In its development 
the stamen at first bears a close resemblance to a rudimentary 
leaf, both in structure and position, and there can be no 
doubt that it is a phyllome, modified into a pollen-produc- 
ing organ. Whether the anther is to be regarded as an out- 
growth of the phyllome, or as its modified upper portion, is 
doubtful ; analogy would indicate the probability of the 
former view. There can be but little doubt that the pollen- 
sacs are to be considered homologous with the microspo- 
rangia of the higher Pteridophytes, and the latter are clearly 
outgrowths (trichomes ?) upon phyllomes. 

528. — The pollen-grains are developed here as in Gymno- 
sperms. from j^oUen mother-cells ; the latter are differentiated 
parenchyma cells, lying in or near the axis of the pollen- 
sacs. Each mother-cell undergoes two divisions (by fission), 
producing four parts, which become as many pollen-grains. 
The mature pollen-grain is a single cell, and consists of a 
mass of protoj)lasm mixed with oil-drops, starch granules, 
etc., surrounded by two investing membranes, an outer hard 
and firm one (the extine), and an inner thin and delicate one 
(the ijitme). In the germination of the pollen-grains, they 
always remain single cells, but a second nucleus appears 
(the representative of the prothallium of the Pteridophytes). 
The development of the pollen-tube takes place as in Gym- 
nosperms, by a prolongation and growth of the intine, but 
here the extine is not slipped off in the process, but only 
pierced in certain thin areas of its surface. Usually but one 
tube issues from each pollen-grain, but in some cases — e.g., 
CEnotliera — two or more are sometimes found. 

529. — The female reproductive organs (individually the 






ANGIOSPERM^. 419 

pistils, and collectively the Gynoecium) normally develop 
upon the uppermost portion of the flower-axis, and within 
the whorl of stamens. They consist of one or more infolded, 
ovuliferous phyllomes {carpophylla) w^hose margins are 
united so as to form separate, or more or less united cavi- 
ties (ovaries). The apical portions of the carpophylla are 
usually extended, terminating in a mass of loose parenchy- 
matous tissue, the stigma. The ovules arise as outgrowths 
(trichomes, in the broader sense of the term) upon some 
portion of the interior surface of the ovary ; they most fre- 
quently develop upon the margins of the carpophylla, 
although they are by no means confined to them. In some 
cases there is but a single ovule in ^^^ _^ 

each ovary, in others they range /miiiiJ ""tt\ 

from a few to several hundred. In ''i 4 '^^'^p.'A^'''^^ 

many cases, especially when the ^m V ''^iwilWW 

ovules are numerous, the ovulifer- ^^-— /^-— ^..^^X 

ous portion of the ovary is devel- ^ B 

oped into a thickened mass of tis- fi?. 305.— Very young ovules of 
sues, the placenta, which projects S^g^Jag^^^SiS^S 
more or less into the ovary cavity. '^^^^.V.^'i^^^l^. 

530.— Each ovule is at first a ulus-the ovule ^l is the young- 

er of the two ; the inner coiit (the 

homOS'eneOUS mass of parenchyma- secnnrline) is just begmnin- to de- 

9 ,-, ,• ,1 1 T velop as anniz-, .^^c ,• 111 5 there are 

tOUS tissue, constituting the body two rings, the upper beins? the ru- 

, n 1 1 \ J? ii 1 dimenrary secundine, the lower 

(or so-called nucleus) 01 the ovule ; the primme. X 140.-After Du- 

a little later a circular ridge arises *^^^''*^"^- 
upon the ovule body ; this grows upward, and forms an in- 
tegument; a second integument frequently form sin exactly 
the same way outside of the first (Fig. 305, A and B). From 
their position when fully formed, these coats have received 
the names primine and secundine, the former being applied 
to the outer, the latter to the inner.* The coats never com- 
pletely enclose the body of the ovule, there always remaining 
a small opening (the micropyle) over its apex (/«, Fig. 306, 

* These terms were so applied by Mirbel, who was not acquainted 
with the order of development of the coats. Schleiden applied them 
in exactly the opposite way, which has led to some confusion. Mir- 
bel's use of the terms, although not as good as Schleiden's, is the pre- 
vailino- one. 



430 



BOTANY. 



A). In their development most ovules, although straight 
(Fig. 306, A) at first, become afterward more or less curved 
ujoon themselves (Fig. 306, B and C). 

The develojiment of tlie embryo sac takes place in a much 
simpler way in Angiosperms than in Gymnosperms.* An 
axial cell enlarges greatly, becoming thus the young embryo- 
sac (Fig. 306, ew). In preparation for fertilization, it divides 
into a row of several (3-6) cells, the uppermost of which 
forms four nuclei, one of which becomes the germ-cell. 
By the absorption of the cell wall, the upper cell fuses 
with the second (which mayor may not contain four nuclei), 
forming a common cavity containing many nuclei or young 




Fig. 306.— Diagrammatic longitudiBal sections of ovules. A^ the straight ovule (or- 
thotropoiiir^) ; k, the body of the ovule, with its embryo sac, em ; ai, the outer ovule 
coat (primine) ; ii, the inner coat (secuncline) ; ?n, the micropyle ; c, the base of the 
ovule, where the coats arise, called also the chalaza ; /, the ovule stalk or funiculus. 
J5,an inverted ovule (anatropous) ; the long funiculus,/, has fused with the primine of 
one side of the ovule and formed the raphe, r. C, a bent ovule (campylotropous).— 
After Prantl. 

cells, several of which, including the Germ-Cell, remain at 
the top, the others (Antipodal Cells) occupying the lower 
part. No endosperm is to be seen at this stage, f 

The fertilization of the germ-cell involves two operations, 
viz.. Pollination — i.e., the dej^osition of the pollen upon the 
stigma, and Fertilization proper. 

* See " Nouvelles Recherclies sur le developpement du sacembryou- 
naire des Phanerogames angiospermes," by Julien Yesque, in Annates 
des Sciences Naturelles, 1879. 

f The endosperm, which here forms after fertilization of the germ- 
cell, may be regarded as a belated piothallium. It is here no longer 
necessary for the prothallium to precede the formation of the germ- 
cell ; there is consequently a considerable retardation in its develop- 
ment. 



ANGIOSPEBM^. 421 

531. Pollination. — As the pollen-grains are entirely want- 
ing in means of locomotion, they are dependent for trans- 
portation to the stigma, upon (1) the wind {miemophilous 
Howers) ; (2) certain contrivances, by means of which insects 
(or rarely birds) are made to carry the pollen from anther to 
stigma {entomoj^hilous flowers) ; (3) the favorable position of 
the anthers and stigmas, bringing the pollen in the open- 
ing anther into contact with the stigmatic surface {auto^ 
gamous flowers). The grasses and sedges, and the oaks, 
beeches, chestnuts, walnuts, birches, and their allies, and a 
few others, have anemophilous flowers. In these the pollen 
is produced in great abundance, and the flowers are small, 
uncolored, and destitute of nectar (honey). An immense 
number of plants have entomophilous flowers ; these are, as 
a rule, large, colored, and provided with nectar-secreting 
glands ; the nectar acts as a bait, and the showiness as a 
guide to honey-loving insects, which, by various structural 
contrivances in the flowers, are made to come successively 
in contact with the anthers of one flower and the stigmas of 
the next, in the first dusting their bodies with pollen, which 
in the second adheres to the stigmas. Autogamous flowers 
are much less numerous than either of the foregoing, and it is 
doubtful whether there are any species of plants all of whose 
flowers exhibit constant autogamy. There are a good many 
plants, however, which have two forms of flowers, viz., large, 
showy, nectar-bearing, entomophilous ones, and small, in- 
conspicuous autogamous ones, generally with a rudimentary 
perianth. Flowers exhibiting this form of autogamy are 
said to be cleistogamous. Examples are to be met with in 

Viola, LitUospermum, Impatiens, etc. ; early in the season 
these have large flowers, which are entomophilous, bnt later 
only small cleistogamous ones appear, and in some species of 

Viola these are subterranean. Without doubt it frequently 
happens that the pollen of anemophilous and entomophilous 
flowers falls upon their stigmas, resulting in accidental auto- 
gamy, but too frequent a recurrence of this is guarded against 
by various structural devices.* 

* Upon this interesting subject tlie student is referred to Mr. Dar- 
win's works, " The Various Contrivances by which Orchids are Fertil* 



b 



4:22 



BOTANY. 



532. Fertilization. — Fertilization takes place as follows . 
Tlie pollen grain, resting upon the moist surface of the 
stigma, absorbs moisture and germinates, sending out a tube 
which penetrates the soft tissues of the stigma and style, 
finally reaching the cavity of the ovary, where it enters the 
micropyle of an ovule (Fig. 307, A). Here it comes in con- 
tact with the ajiex of the ovule body, through whose tissues 
it forces its way until it reaches the embryo sac ; in some 

cases, however, the 
embryo sac has grown 
out through the apex 
of the ovule body 
into, and occasionally 
through the micro- 
pyle, thus meeting the 
pollen - tube. The 
transfer of the con- 
tents of the j)ollen- 
tube to the germ-cell 
has never been ob- 
served, but doubtless 
it takes place by diffu- 
sion through the ^o\- 
len-tube and embryo 
sac. The first result 
of fertilization is the 
formation of a wall of 
cellulose around the 
germ-cell ; the latter 
soon divides trans- 
versely one or more times, and thus gives rise to a row of 
cells, the suspensor, at the free extremity of which a rudi- 
mentary embryo is soon formed by the fission of cells in 
three planes (Fig. 307). Simultaneously with the foregoing 




Fig. 307.— J., a longitudinal section of the anatro- 
pous ovule of Viola tricolor^ after fertilization, pi, 
the placenta ; w, the raphe, swollen at this point ; a, 
the outer coat of the ovule ; i, the inner ; p, the pol- 
len-tube which has entered the micropyle ; e, em- 
bryo Sac. with the very young embryo at the micro- 
pyiar end, and numerous free endosperm cells at the 
other. B, apex of embryo sac, e (much more mag- 
nified) ; eb. very young embryo of two cells, support- 
ed by a two-celh'd suspensor. C, the same, further 
advanced All the figures highly magnified. — After 
Sachs. 



ized by Insects ; " " The Effects of Cross and Self-Fertilization in the 
Vegetable Kingdom ; " " The Different Forms of Flowers on Plants of 
the Same Species." Also Lubbock's " British Wild Flowers Considered 
in Relation to Insects," and Dr. Gray's " How Plants Behave." 



ANOIOSPERM^. 



423 



development in the apical portion of the embryo sac, tliere is 
a corresponding one in the basal portion. The protoplasm 
gathers about certain points, and gradually condenses so as 
to form as many free and naked cells (Fig. 308). These 
soon become covered with cell-walls, and they then multiply 
rapidly by fission, until they 
fill up the embryo sac with a 
continuous tissue, the endo- 
sperm. (Consult p. 41, and 
Fig. 33, A and B. ) 

533. The Development of Fig. 308.— Posterior part of the em- 
XT -n -u ^^ /T?"^r, QAo „v, 1 ^^i"yo Pac of Viola tricolor, e, its wall ; s, 
the Embryo. (l^lgS. 309 and cavity of the .ac; A' /r, youn- endo 
^10^ A« c;fnfprl nhnvp nno of ^Peim-cells which have formed in the 
6l\J}. — iVS Staiea auove, out Ol protoplasm, pr. mghly magnified.— 

the first results of the fertili- After sachs. 
zation of the germ-cell is the formation of a row of from 
two to many cells, the suspensor or pro-embryo, the first or 
proximal cell of vdiich is attached to the wall of the 
embryo sac close to the micropyle of the ovule ; its distal, or 
free end, always grows toward the interior of the ovule, and 





Fig. 309. — Embryos of AUium cepa. I., very young Ptage ; e, 5, cells of suspensor ; 
a, the single cell constituting the embryo ; a?, an unfertilized germ-cell. //., an older 
stage, the embryo now two-celled , es, the wall of the embryo sac. III., a still later 
Much maL'nified.— After Sachs. 



its last cell becomes transformed by successive fissions into a 
several-celled surface (/.,Fig. 310) ; by a continuation of the 
process a many-celled solid body is formed (IL, Fig. 310) ; 
partitions then arise in the cells parallel to the surface, and 
the external layer of daughter-cells thus formed constitutes 
the dermatogen or primary epidermis {III.; Fig. 310), 



424 



BOTANY. 



About this time there is in most cases a slight differentiation 

of tlie inner cells, 
foreshadowing the 
future tissue sys- 
tems (///. and 
IV., Fig. 310). A 
little later the cot- 
yledons (one or 
two) appear ; in 
the Monocotyle- 
dons, in one side of 
the thallus - like 
structure a depres- 
sion forms, which 
becomes the ininc- 
timi vegetationis of 
the embryo, and 
marks the limits of 
the stem and single 
cotyledon ; in the 
Decotyledons two 
cotyledons grow 
out symmetrically 
from the disral end 
of the thallus-like 
structure, and the 
depression between 
them becomes the 
vegeta- 
tionis {V., Fig. 
310). The root is 
the last portion of 
the embryo form- 
ed ; its cap (the pil- 
eorhiza) is develop- 
ed from a layer of 
cells resulting from 
the successive fis- 
sion of the penultimate cell of the suspensor, the hypophy- 




Fig. 310.— Development of the embryo of Capsella 
Bursi I -past07is (highly magnified). /., i). s^iispensor, or ^^/^,^/^, „, 
pro-embryo of five cells, and terminated bv a four-celled JJliiot'VLviii 
embryo; 1-1, the longitudinal wall which diviiled the 
first embrj^o-cell into two cells; 2-2, transverse wall 
which divided each cell of the two-celled embryo, mak- 
ing it four celled. //., ■«, suspensor; h, the hypophysis, 
the basal part of the embrj'O formed by the division of 
the end cell of the suspensor ; the shaded portion of the 
embryo is the dermatogen or primary epidermis ///., 
embryo further advanced ; the inner shaded cells con- 
etiiute the plerome, between these and the dermatogen 
to the right and left are the cells of the periblem ; the 
hypophysis is divided into two cells, A, h'. IV., still 
older condition. F., embryo considerably advanced ; 
€, c. cotyledons ; s, apes of stem ; the dermatogen, peri- 
blem, and. plerome shown as before ; ^o, the rudiment- 
ary root, and root-cap formed from the cell h' of III. 
and 7F.— After Hanstein. 



ANOIOSPERMJE. 425 

sis {U, Fig. 310, //., ///., IV., v.). The growing points of 
both root and stem develop in all cases from masses of 
small cells^ and never from single apical cells. 

Tlie development of tlie embryo may be studied by selecting the 
young ovaries of Gapsella Bursa-jpastoris, or Lepidium intermedium, and 
dissecting out tlie ovules in a solution of potassic liydrate, and after- 
wards transferring tliem to a solution of glycerine and water. Speci- 
mens prepared in this way show clearly the embryo sac with the con- 
tained suspensor and embryo when examined by means of a magnify- 
ing power of from one hundred and fifty to four hundred diameters. 
When they have been made too transparent by this treatment, their 
walls may be rendered more opaque by the addition of a dilute solution 
of alum. The young embryo may sometimes be separated from the 
ovule by a gentle pressure upon the top of the cover-glass. 

534. The Endosperm. — Dnring the early part of the de- 
velopment of the embryo, just described, the formation of 
endosperm cells Avithin the embryo sac takes place with great 
rapidity ; in most cases the growth of the endosperm is so 
great as to displace the greater part or even the whole of the 
surrounding tissues. The cells of the endosperm contain 
large quantities of nutrient matters, which are at first in so- 
lution, but which later may pass into a less soluble condition. 
The growing embryo is imbedded in the endosperm, and as 
the former increases in size, the latter is displaced and ab- 
sorbed. In many cases the growth of the embryo is arrested 
before the endosperm is all absorbed — e.g., in Eanunculaceae, 
Yiolaceae, Solanacese, Euphorbiacese, Palmaceae, Liliaceae, 
Graminese, etc. ; in other cases the embryo continues to grow 
until it has entirely absorbed the endosperm — e.g., Cruciferae, 
Rosacese, Myrtacese, Compositse, Salicacese, Cupuliferse, 
Alismacese, etc. 

535. The Perisperm. — It rarely occurs that the endo- 
sperm develops but slightly, and in such cases there is a con- 
siderable development of the tissues of the ovule surround- 
ing the embryo sac, constituting the perisperm ; in such 
cases nutrient matters are contained in the latter, which 
functionally replaces the endosperm. Examples of this 
structure occur in Nymphseacese, Piperaceae, and Caunace^. 

536. — During the growth of the embryo the ovule and 
ovary undergo considerable changes. The outer coat of the 



426 BOTANY. 

ovule becomes hardened by tlie conversion of parenchyma 
into sclerenchyma, thus forming the testa ; in other cases it 
becomes more or less pulpy, as in Magnolia, Pceonia, etc. 
The outer coat is liable to be much modified in form also, 
being sometimes developed into thin wings, or a tuft or 
covering of hairs, as in Big7i07iia, Asclepias, Gossypium., etc. 
The inner coat usually undergoes little change, generally be- 
coming thin and dry. The ovary in many cases becomes 
hard and dry — e.g., in Cupuliferae and Leguminosse ; in 
others it is more or less pulpy, as in the Cherry, Plum, 
Blackberry, etc. Both ovule and ovary at maturity (now 
called seed and pericarp respectively, and the latter, with all 
its contained seeds, the fruit) spontaneously separate from 
their supporting parts, by the breaking away of the walls of 
certain layers of cells. 

The development of tlie flower as a whole, or, as it is termed, the Or- 
ganogeny of tlie flower, is an important and instructive subject of 
study. The law of greater structural similarity in the earlier stages of 
organisms becomes very evident when we look carefully into the de- 
velopment of flowers. Very many flowers which, when fully formed, 
have little resemblance to each other, are found to be exactly alike in 
their earlier stages. Relationsliips are thus indicated where they 
would otherwise hardly be detected. 

Without entering further upon this subject, which would require 
several volumes for its full treatment, it need only be said here that 
all the floral organs are essentially alike in form and structure upon 
their flrst appearance ; the sepals, petals, stamens, and pistils appear 
at first as small papillae, and it is only after they have grown somewhat 
that the nature of the nascent organ can be determined by its shape. 
Moreover, it is found (as has so often been seen in the development of 
animals) that the rudiments of some organs which are wanting in the 
fully-formed flower are present in its earlier stages, a fact of no less 
significance in the comparative anatomy of plants than of animals. 

The general appearance of the parts of the very young flower, and 
their development, are well shown in the accompanying figures from. 
Hofmeister (Figs. 311-313).* 

Glossolog'y of Angiosperms. — The great number of species of An- 
giosperms and the multitude of forms assumed by different parts of 

* The student who wishes to study this subject further may profit- 
ably consult Hofmeister's " Allgemeine Morphologie der Gewachse,* 
Leipsic, 1868, and Payer's " Organogenie de la Fleur," Paris, 1857. 



GLOSSOLOGY OF ANQIOSPERMS. 



427 



the plant, bave made necessary the use of many descriptive terms, the 
principal ones only of which will be noticed here. 

Inflorescence. — The arrangement of the flowers, whether singly, or 
in groups upon a more or less branched axis, is termed inflorescence. 
The branching of the axis in flower groups is almost universally mono* 




wmm 



Pis. 311. 




Fig 313. 

Pigs. 311-13.— Three puccessive stages in the development of the flower of the Rose 
(Rosa canina). In all the figures, c, e. ar^^ the sepals ; p, p, petals ; st, stamens ; cp, 
carpels or pistils. Magnified.— After Hofmeister. 

podial, a few cases only (and they doubtful ones) have been regarded as 
dichotomous. 

Monopodial flower clusters fail under the two types BotJ'i/oae and Ci/- 
mose, referred to in paragraph 177 (page 139). In Botryose inflores- 



428 BOTANY. 

cence the flowers afe properly lateral upon tlie main axis, or tlie sec 
ondary axes. The flowers develop in acropetal (centripetal) order, and 
when the axis continues to grow the cluster may become indefinitely 
extended, whence it is called indeterminate. In Cyniose inflorescence 
every flower is properly terminal upon a main axis or one of the sec- 
ondary ones. In every flower cluster the main axis is first terminated 
by a flower ; lateral branches (secondary axes) then arise at some dis- 
tance below the apex, and each of these is terminated by a flower ; 
lateral branches terminated by flowers arise on the secondary axes, and 
so on. The flowers thus develop in basipetal (centrifug'al) order. From 
the fact that every axis is terminated by a flower, such clusters are 
often called determinate. This distinction into indeterminate and deter- 
minate is, however, a misleading one, for some botryose inflorescences 
are in fact determinate — e.g., the Umbsl and Head ; while, on the other 
hand, most of the cymose flower clusters are capable of indefinite ex- 
tension, as is notably the case with the Helicoid and Scorpioid forms. 
It not infrequently happens that in large flower clusters a |)art of the 
branchincr is of one type and the remainder ot the other ; all such case? 
may be considered as examples of mixed infl jrescence. 

The most important of the terms in common use are given in th^ 
following table, of inflorescences : 

A. Botryose Inflokescence. 

I. Flowers solitary in the axils of the leaves — 

e.g., Vinca Solitary Axillary; 

II. Flowers in simple groups. 

1. Pedicellate. 

{a) On an elongated axis : pedicels about 

eqttal — e.g., Mignonette Haceme. 

(&) On a shorter axis ; lower pedicels 

longer — e.g., Hawtliorn Corymb. 

(c) On a very short axis ; pedicels about 

equal — e.g.. Cherry Umbel. 

2. Sessile. 

(a) On an elongated axis — e.g., Plantain.S'pike. 
Var. /3. Drooping, and scaly bracted — 

e.g. , Poplar » . . . . Catkin. 

Var. y. Thick and fleshy — e.g., Indian 

Turnip Spadix. 

(&) On a very short axis — e.g.. Clover. . .Head. 
IIL Flowers in compound groups. 
1, Regular. 

(a) Racemes in a raceme — e.g., Smilacina.Coioa-povLnd Racem.e. 

(6) Spikes in a spike — e.g., WJieat Com.pound Spike. 

(c) Umbels in an umbel — e.g., Pars/iij?.. Compound Um.bel._ 



GLOSSOLOGY OF ANGLOSPERMS. 429 

{d) Heads in a raceme — e.g.. Ambrosia. .Heads Racemose. 

{e) Heads in a spike — e.g., Liatris Heads Spicate. 

And so on. 
2. Irregular. 

Racemosely or corymbosely compound — 

e.g., Catalpa Panicle. 

Compound forms of tlie panicle itself are common — e.g.^ panieted 
i£ads in many Compositse, panicled spikes in many grasses. 

B. Cymose Inflorescence. 

I. Flowers solitary ; terminal — e.g., Anemone 

nemorosa Solitary Terminal, 

II. Flowers in clusters (Cymes). 

1. Lateral brandies in all parts of the flower 

cluster developed — e.g., Cerastium Forked Cyme, or 

Dichasium. 
(This is tlie Biparous, and so-called Dichotomous Cyme of authors.) 

2. Some of the lateral branches regularly suppressed. 

(a) The suppression all on one side — e.g., 

Hemerocallis Helicoid Cyme, or 

Bostryx. 
(&) The suppression alternately on one 

side and the other — e.g., Drosera. . .Scorpioid Cyme, or 

Cicinnus. 
(The last two are frequently not distinguished from one another, and 
are called Monocliasia, Uniparous Cymes, or Facse Racemes.) 

G. Mixed Inflorescence. 

1. Cymo-Botryose, in which the primary in- 

florescence is botryose, while the sec- 
ondary is cymose, as in Horsechestnut. . . Cymo-Botrys, 
(This is sometimes called a Thyrsus.) 

2. Botryo-Cymose, in which the primary in- 

florescence is cymose, while the sec- 
ondary is botryose — e.g., in many Com- 
posim Botry-Cyme. 

Floral Symmetry. — The parts of the flower are mostly arranged 
in whorJs, which are distinctly separated from each other {cyclic flow- 
ers) ; in some cases they are arranged in spirals, with, however, a dis- 
tinct separation of the diSerent groups of organs Qiemicyclic flowers) ; 
in still other cases the arrangement is spiral throughout, with no 
separation of the groups of organs {acyclic flowers). 



430 BOTANl. 

In cyclic flowers tliere are most frequently four or five wliorls, viz. : 

1. The Calyx, composed of (mostly) green sepals. 

2. The Corolla, composed of (mostly) colored petals. 

3. (4.) The And) uiciam, composed of one or two whorls of stamens. 
4 or 5. The Gynoicium, composed of carpels. 

These whorls usually contain definite numbers of organs in each ; in 
many cases tlie numbers are the same for all the whorls of the flower 
(isomerous flower) ; when the numbers are different the flower is said 
to be heteromerous. 

The terms which denote these numerical relations are : monocyclic, 
applied to a flower having only one cycle ; hicyclic, two cycles ; tricyclic, 
three cycles ; tetracyclic, four cycles ; penta yclic, five cycles, etc. ; 
monomerous, applied to flowers each cycle of which contains one mem- 
ber ; dimer(.us, two members ; trimerous, three members ; tetramerous, 
four members ; pentamerous, five members. 

These relations can be briefly indicated by using symbols and con- 
structing floral formulae, as follows : 

Cas, Cos, An5, Gus = a tetracyclic pentamerous flower ; 
Caa, C03, Ana + 3, Gua = a pentacyclic trimerous flower. 

Most commonly the members of one whorl alternate with those of 
the whorls next above and below ; in a few cases, however, they are 
opposite (or superposed) to each other. These relations may be indi- 
cated by a modification of the floral formulae given above, as follows, 
where the members are alternate : 



Gn 
An 
An 
Co 
Ca 
B 



When they are opposite the arrangement is as follows : 

Gn 

An . . 

Co . 

Ca 

B 

In both these formulae the position of the parts of the flower with 
respect to the flowering axis is indicated by the position of the bract 
B, which is always on the anterior side, while the axis is always pos- 
terior. 

When all the members on each whorl are equally developed, having 
the same size and form, the flower may be vertically bisected in any 
plane into two equal and similar halves; it is then actinomorphir, 
(= regular, and polysymmetrical). When the members in f ach whorl 



GLOSSOLOGY OF ANGIOSPERMS. 431 

are unlike in size and form, and the flower is capable of bisection in 
only one plane, it is zygomoophic (= irregular, and monosymmetrical). 
In the latter there is generally more or less of an abortion of certain 
parts — i.e., one or more of the sepals, petals, stamens, or pistils are but 
partially developed, appearing in the flower as rudiments only. Some- 
times this is so marked as to result in the complete suppression of cer- 
tain parts. 

It not infrequently happens in both actinomorphic and zygomorphic 
flowers that entire whorls are suppressed ; this gives rise to a number 
of terms, as follows : 

When all the whorls are present (not necessarily, however, all mem- 
hers of all the whorls) the flower is said to be complete ; when one or 
more of the whorls are suppressed, the flower is incomplete. 
As to its perianth, the fl(jwer is said to be 
Dichlamydeous, when both the whorls of the perianth are present j 
Monochlamydeous, when but one (usually the calyx) is present ; 
Apetalous, when the corolla is wanting ; 

Achlamyde(MS, ov naked, when both calyx and corolla are wanting; 
As to its sexual organs, the flower is 
Bisexual (or hermaphrodite) when stamens and pistils are present ; 
Unisexual, when, of the essential organs, only the stamens are pres- 
ent (then staminate), or only the pistils (then pistillate) ; 
Neutral, when both stamens and pistils are wanting ; 
Collectively, bisexual flowers are said to be monoclinous ; unisexual 
flowers, diclinous ; while in those cases where some flowers are bisex- 
ual and others unisexual they are, as a whole, said to be polygamous. 
Diclinous flowers are further distinguished into 

Monoecious, when the staminate and pistillate flowers occur on the 

same plant, and 
Dioecious, when they occur on different plants. 
The Perianth. — In a large number of flowers the parts of the 
calyx and corolla (sepals and petals) are distinct — i.e., not at all united 
to one another ; such are said to be chorisepalous^ as to the calyx, and 
choripetalous as to the corolla. The terms polyseyalous and polypetal- 
ous are the ones most commonly used in English and American books 
on botany, although they manifestly ought to be used as numerical 
terms. Eleutheropetalous f and dialypetalous % are also somewhat used, 
especially in German works. 
The numerical terms usually employed are mono-,% di-, tri-, tetra-, 

* From Greek x'^pK^'-'^-, to sever, to separate. 

f From Greek ekevBepoQ, free. 

X From Greek diaTiveiv, to part asunder. 

§ The terms moncsepalous and monopetalous were formerly used w'th 
a different meaning from that given here ; they were applied to the 
forms now called gamosepalous and gamopetalous. This use, errone- 



132 BOTANY. 

penta-sepalous, etc. , and mono-, di-, tri-, tetra-, penta-petalous, etc., mean. 
incr of one, two, three, four, five sepals or petals respectively. Polysepa- 
Ions and polypetalous are properly used to designate " a considerable but 
unspecified number" of sepals or petals,* 

In some flowers tlie sepals or petals, or both, are united to one 
another, so that the calyx and corolla are each in the form of a single 
tube or cup. This union of similar parts is called coalescence. The 
terms gamosejialms f and gamopeta ous (or sympetalous) are used in such 
cases. Monosepalous and monopetalous, still used in this sense in many 
descriptive works, sboulJ be reserved for designating the number of 
sepals or petals in calyx and corolla respectively. 

Not infrequently the calyx and corolla are connately united to each 
other for a less or greater distance. This union of dissimilar whorls is 
termed adtiation, and the calyx and corolla are said to be adnate to 
each other. 

The Androecium. — The number of stamens in the flower or the 
anuroecium is indicated by such terms as 

Monandrous, signifying of one stamen ; 

Diaiidrous, of two stamens ; 

I'riandrous, of three stamens ; 

Tetrandrous, of four stamens — when two of the stamens are longer 
than the other two, the androecium'is said to be didynamous; 

Pentandrous, of five stamens ; 

Htxandrous, of six stamens ; when four are longer than the remain- 
ing two, the androecium is said to be tetradynamous. 

Other terms of similar construction are used, as heptandrous, seven 
stamens ; octandrous, eight ; enneand' ous, nine ; decandrous, ten ; dodec- 
androus, twelve; and polyandrous, many or an indefinite number of 
stamens. 

The stamens may be in a single whorl {monocyclic), in which case, if 
agreeing in number with the rest of the flower, the androecium is said 
to be isostemonous ; they are often in two wiiorls {bycycUc), and when 
each whorl agrees with the numerical plan of the flower, the androe<. 
cium is diplostemonous. 

The various kinds of coalescence require the use of special terms. 
When there is a coalescence of the filaments the androecium is 

Monndelphou.s, when the stamens are united into one set; 

Diadelphous, when united into two sets ; 

Triadelphoiis, when united into three sets, etc. 

ous as it obviously is, has not yet been abandoned in works on descrip- 
tive botany. 

* Dr. Gray throws the weight of his authority in favor of this us« of 
these terms (" Structural Botany," 1879, p. 244). 

X From Greek ju/nos, union. 



GLOSSOLOGY OF ANGIOSPERMS. 433 

Wlien there is a coalescence of tlie anthers tlie androecium is syii 
genesious or synantherous. 

The stamens may be adnate to the petals, when they are epijpetalous ; 
in some cases they are adnate to the style of the pistil, as in the 
Orchids ; such are said to be gynandrous. 

The principal terms which designate the structural relation between 
the anther and filament in individual stamens are : 

Adnate, applied to anthers which are adherent to the upper or lower 
surface (anterior or posterior) of the filament ; when on the upper 
surface the anthers are introrse ; when on the lower, extrorse. 

Innate, applied to anthers which are attached laterally to the upper 
end of the filament, one lobe being on one side, the other on the oppo- 
site one. The part of the filament between the two antlier-lobes is 
designated the connective ; it is subject to many modifications of form, 
and often becomes separable by a joint at the base of the anther from 
the rest of the filament. 

Versatile is applied to anthers which are lightly attached to the top 
of the filament, so as to swing easily ; these may also be introrse or 
extroise. 

The Gynoecium. — The Gynoecium is made up of one or more carpels 
{carpids or carpophylla)—i.e. , ovule-bearing phyllomes, and it is said to 
\iQmono-, di-, tri-, tetra-, penta-, etc., &nd poly carpellary, according as it 
has one, two, three, four, five, to many carpels. In old books the 
terms monogynous, digynovs, trigynous, etc., meaning of one, two, three, 
etc., carpels, are used instead of the more desirable modern ones. When 
the carpels are more than one they may be distinct, forming the apo- 
carpous gynoecium ; or they may be coalescent into one compound or- 
gan, the syncarpous gynoecium. In the former case the term pistil is 
applied to each carpel, and in the latter to the compound organ. Pis- 
tils are thus of two kinds, simple and compound ; the simple pistil is 
synonymous with carpel ; the compound pistil with syncarpous gynoe- 
cium 

In the simple pistil the ovules actually grow out from the united 
margins (the ventral suture) of the carpophyllum ; the internal ridge or 
projection upon which they are borne is the placenta. Sometimes the 
ovules are erect— i.e., X\\Qy grow upward from the bottom of the ovary — 
and when single appear to be direct continuations of the flower axis 
(Fig. 304). Suspended ovules — i.e., those growing from the apex of the 
ovary cavity — are also common. 

In compound pistils the coalescence may be, on the one hand, of closed 
carpels, and on the other of open carpels. In the former case the pis- 
til has generally as many l"Culi (cavities or cells) as there are carpels ; 
this is expressed by the terms uni-, M , tri-, quadri-, and so on to multi- 
locular. Such pistils have axile placentae — i.e., they are gathered 
about the axis of the ovary, e.g., Hypericum. In the case of compound 
pistils formed by the coalescence of open carpels, the margins only of the 



434 BOTANY. 

latter unite, forming a common ovary cavity ; here the placentae gener- 
ally occur along the sutures, and are said to be parietal — i.e., on the 
walis, Between such unilocular pistils and the multilocular ones 
described above there are all intermediate gradations. In odb series of 
gradaiions the placentae project farther and farther into the ovary cav- 
ity, at last meeting in the centre, when the pistil becomes multilocular 
with axile placentae. On the other hand, a multilocular pistil sometimes 
becomes unilocular by the breaking away of the partitions during 
growth. In such a case the placentae form a free central column, 
commonly called 9. free central placenta. 

In other cases a free placental column of an entirely different origin 
occupies the axis of a unilocular, but evidently polycarpellary pistil. 
In Anagallis, for example, the placental column grows from the base 
of the ovary cavity, and there is at no time a trace of partitions (see 
illustrations of the Order Primulaceae, p. 507). 

The Gynoecium may be free from all the other organs of the flower, 
which are then said to be liypogynous,^ and the gynoecium itself w^ 
perior. Sometimes the growth of the broad flower-axis stops at its 
apex long before it does so in its marginal portions ; a tubular ring is 
thus formed, carrying up calyx, corolla, and stamens, which are then 
said to he perigynovs,\ and the gynoecium half inferior. These terms 
are used also in the cases where the gynoecium is similarly surrounded 
by the tubular sheath composed of adnate calyx, corolla, and andrce- 
cium. In some nearly related cases, in addition to the structures de- 
scribed above as perigynous, there is a complete fusion of the calyx, 
corolla, and stamen -bearing tube with the gynoecium. so that the ovule- 
bearing portion of the latter is below the rest of the flower, e.g., Com- 
positae. The perianth and the stamens are said to be epigynousX in such 
flowers, and the ovary is inferior. Some cases of epigyny are doubtless 
to be regarded as due to the adnation of the calyx, corolla, stamens, 
and ovaries ; in others, the ovaries are adnate to the hollow axis which 
bears the perianth and stamens ; in still others, it seems probable that 
the hollow axis is itself ovule-bearing, and that the true carpels are 
borne on its summit. 

Certain terms descriptive of relations between the stamens and pis- 
tils which have recently come into use require explanation here. 

In many flowers the stamens and pistils do not mature at the same 
time, such are said to be dichogamous ; when the stamens mature be- 
fore the pistils the flower is proterandrous ; and when the pistils ma- 
ture before the stamens they are proterogynous. 

In some species of plants there are two or three kinds of flowers, 

* From Greek vito, under, and yvvrj, female — i.e., the pistil. 
f From the Greek Trepi, about, etc. 
X From the Greek eni, upon, etc. 



GLOSSOLOGY OF ANGIOSPEBMS. 435 

differing as to tlie relative lengths of the stamens and styles ; these are 
called heterogonous^ or heterostyled. When there are two forms, viz., 
one in -v^hicli the stamens are long and the styles short, and the other 
with short stamens and long styles, the flowers are said to be dimorph- 
ovs, or more accurately Juterogonous diniorpfious, and the forms are 
6.\Qi\rxgmB\ied. Si.9, short- styled &r\di Inng-s'y ed When, as in some spe- 
cies of Oxalis, there are three forms, viz., long-, mid-, and short-styled, 
the term trimorphous (or better heterogoaous tiimorp}i<m>) is used. 

The Fruit. — The fruit may include (1) only the ripened ovary with its 
contained seeds — eg., the bean ; or (2) these with an adnate calyx or re- 
ceptacle — e.g. , tlie apple. Many chanoes frequently take place in ripen- 
ing, such as (1) an increase in the number of cells by the formation of 
false partitions, or (2) a decrease in their number by the obliteration of 
some ; (3) the growth of wings or prickles upon the exterior of the ovary ; 
(4) the thickening and formation of a soit and juicy pulp; (5) the 
hardening of some portions of the ovary wall by the development of 
sclerenchyma ; (6) the thickening and growth of the calyx or recep- 
tacle. 

In cases where in the ripening the ovary walls remain thin, and 
eventually become dry, the fruits are said to be dry — e.g., in the bean ; 
where the walls become thickened and moi-e or less pulpy, they are 
flesJiy — e.g., the peach. These terms are also used in reference to the 
fruit when it includes an adnate calyx or receptacle. In many fleshy 
fruits (developed from carpels) the inner part of the pericarp wall is 
hardened ; the two layers are then distinguished as exocarp and endo- 
carp ; when there are three layers the middle one is the mes< e irp. 

The opening of the fruit in order to permit the escape of the seeds is 
called its dehiscence, and such fruits are said to be dehiscent ; those 
which do not open are indehixicent. In fruits developed from single 
carpels dehiscence is generally through the ventral or dorsal suture, or 
both ; in those developed from compound pistils the partitions may 
split, and thus resolve each fruit into its orio-inal carpels {septicidal 
dehiscence) ; or the dorsal sutures may become vertically ruptured, 
thus opening every cell (loculus) by a vertical slit {loculicidal dthis- 
cence). Among the other forms of dehiscence only that called circum- 
cissile and the irrfgular need be mentioned ; in the former a transverse 
slit separates a lid or cap, exposing the seeds ; in the latter an irregu- 
lar slit forms at a certain place, and throujrh this the seeds escape. 

The principal fruits may be distinguished by the brief characters 
given in the following table :f 

* Proposed by Dr. Gray, Am. NaUirali^i, Jan., 1877. 

f This is based upon Dr. Dickson's classification as modified by 
Professor Balfour in the article " Botany " in the ninth edition of the 
" Encyclopaedia Britannica," Vol. IV., p. 153. 



436 BOTANY. 

A. Monogyncecial fruits, formed by the gynoecium of one flower. 

I. Capsulary fruits. Dry, deliiscent, formed from one pistil. 

1. Monocarpellary, 

{a) Openiag by one suture — e.g , Cnltlia Follicle. 

(&) Opening by both sutures — e g.,Pea Legume. 

2. Bi-polycarpellary— e.^., Viola „ Capsule. 

Var. a. Dehiscence circumcissile — e.g., Ana- 
ga' is. Pyxis. 

Var. &. Dehiscence by the fallintj away of 
two lateral valves from the two per- 
sistent parietal placentae — e.g.. Mus- 
tard Silique. 

II. Schizocarpic fruits. Dry, breaking up into one-celled inde- 
hiscent portions. 

1. Monocarpellary, dividing transversely — e.g., Des- 

modium Loment. 

2. Bi-polycarpellary. 

{a) Dividing into achene-like or nut-like parts 
(nutletfi), no forked carpophore — e.g., LitJi- 
ospermum Carcerulus. 

(6) Dividing into two achene-like parts {meri- 
caips), a forked carpophore between them 
— e.g. , Umhelliferm , Cremocarp. 

III. Achenial fruits. Dry, indehiscent, one-celled, one or few 
seeded, not breaking up. 

1. Pericarp hard and thick — e.g., Oak Nut. 

3. Pericarp thin — e.g., Sunflower Achene. 

Var. a. Pericarp loose and bladder-like — e.g., 

Chenopoaium Utricle. 

Var. 6. Pericarp consolidated with the seed — 

e.g.. Grasses Caryopsis. 

Var. c. Pericarp prolonged into a wing — e.g., 

Ash Samara. 

IV. Baccate fruits. Fleshy, indehiscent ; seeds in pulp. 

1. Kind firm and ha^rd— e.g., Pumpkin Pepo. 

2. Rind thin — e.g., Goosebenp Berry. 

V. Drupaceous fruits. Fleshy, indehiscent ; endocarp indurated, 
usually stony. 

1. One stone, usually one-celled — e.g.. Cherry Drupe. 

3. Stones or papery carpels, two or more — e.g., 

Apple Pome. 

VI. Aggregate fruits. Polycarpellary ; carpels always distinct. 
The forms of these are not well distinguished. In many Ranuncu 



TISSUES OF ANGI0SPERM8. 437 

laceae there are numerous aclienes on a prolonged receptacle ; in Mag- 
nolia numerous follicles are similarly arrano;ed ; in the raspberry many 
drupelets cohere slightly into a loose mass, which separates at maturity 
from the dry receptacle ; in the blackberry similar drupelets remain 
closely attached lo the fleshy receptacle ; in the strawberry there are 
many small achenes on the surface of the fleshy receptacle ; finally, in 
the rose several to many achenes are enclosed within the hollow and 
somewhat fleshy receptacle. 

B. Polygyncecial fruits, formed by the gynoecia of several flowers. 

1. A spike with fleshy bracts and perianths — e.g.. 

Mulberry SoROSis. 

2. A spike with dry bracts and perianths — e.g.. 

Birch Strobile. 

3. A concave or hollow, fleshy receptacle, enclosing 

many dry gynoecia — e.g.. Fig. Syconus. 

The Seed. — Many of the terms used in the description of the ovule 
are applied also to the seed. However, the modifications which most 
of the parts undergo render necessary some additional terms. Thus 
the outer integument is generally so thickened and hardened that it is 
commonly called the testa. The inner is sometimes called the tegmen. 
In some seeds the outer coat becomes fleshy, in which case they are 
baccate (berry-like) ; in others the outer part of the testa is fleshy and 
the inner hardened, so that the seed is drupe-like (drupaceous). Occa- 
sionally an additional coat forms around the ovule after fertilization; 
it differs somewhat in nature in different plants, but all are commonly 
included under the name aril — e.g., May Apple. 

The testa may be prolonged into one or more flat extensions ; such a 
seed is winged — e.g., Catalpa. Its epidermal cells may be prolonged 
into trichomes, forming the comose seed — e.g., cotton. 

The embryo either occupies the whole of the seed cavity, in exalbu- 
minous seeds, or it lies in or in contact with the endosperm, in the 
albuminous seeds. It is straight — e.g., the pumpkin; or variously 
curved and folded — e.g., in Erysimum; where the cotyledons are in- 
cumbent, and in Arabis, where they are accumbent. 

537.— The Tissues of Angiosperms. — The epidermis of 
Angiosperms does not differ in any marked way from that 
of the Gymnosperms and the Pteridophytes. The principal 
differences are that, as a rule, the stomata are more numer- 
ous, and the trichomes, which are much more commonly 
present, show greater variations in form and structure. It 
is noticeable, f;^rthermore, that in both these points the 
Dicotyledons excel the Monocotyledons. 



4o8 BOTANY. 

538. — Tlie tissues of the fundamental system in the An- 
giosperms are, in general, sharply set off from those of 
the epidermal and fibro-vascular systems. In the annual 
stemmed speeies the fundamental tissues constitute tlie great- 
er part of the stems, but in perennial-stemmed species there 
is proportionately less of these, and more of the fibro-vascular 
tissues ; in the former the principal tissue in the funda- 
mental system is parenchyma, which occupies the interfascic- 
ular spaces, as well as the greater part of that lying between 
the bundles and the epidermis — i.e., in the cortical region. 
In perennials, on the contrary, the interfascicular spaces are 
in many cases occupied by sclerenchyma, and the cortical 
region either entirely disappears (as in Dicotyledons) or it 
becomes filled with sclerenchymatous or fibrous tissue. 

In the leaves the fundamental system rarely includes more 
than chlorophyll-bearing parenchyma, while in the parts of 
flowers a similar tissue is found, which is, however, generally 
wanting in chlorophyll. The succulent j^arts of fruits, 
whether phyllome or caulome structures, are comj^osed of 
parenchyma of the fundamental system. 

539. — The fibro-vascular bundles of the stems of Angio- 
sperms are entirely of De Bary's ^^ collateral" class — that is, 
each bundle in cross-section presents more or less distinctly 
two sides, viz., xylem and phloem. Each of these sides, as 
previously described (paragrai3h 147), generally contains 
parenchymatous, fibrous, and vascular tissues, the latter 
tracheary in the xylem, and sieve in the phloem. 

540. — The disj^osition of the bundles in the Angiosperms 
is for the most joart dependent upon the position of the leaves. 
Nearly all the first-formed bundles are of the kind termed 
^^ common bundles" — that is, they extend on the one hand 
into the leaf, and on the other down into the stem. In 
Fig. 314 there pass down from each leaf three bundles ; at 
the lower internode these are, on the left, a, I, c, and on the 
right, d, e, /. At the next internode, where the leaves 
stand at right angles to the lower ones, there are three 
bundles again, g, h, i, and Z;, I, m ; these are largest at their 
points of curvature, and they dwindle in size as they pass 
downward and finally unite with the bundles from the lower 



TISSUES OF ANGIOSPEBMS. 



iSd 




Fig. 314.— Showing the disposition of thefibro-vascular bundles in the Btem of Clem- 
atis yiticella. a, b, c, — d, e, f, the bundleH f i om the lower pair of leaves; g, h, i, — 
k, I, m, the bundles from the second pair of leaves ; n, o, p, —q, r, s, the bundles 
from the third pair of leaves ; t» and t, the median bundles of the fourth pair of 

leaves ; a, 13, y, d, pairs of rudimentary leaves not yet supplied With bundles. — 

After Nageli. 



440 



BOTANY. 



pair of leaves. The bundles from the third internode pass 
downward, and in like manner join those from the second 
pair of leaves, and so on. Thus in such a stem every bundle 

passes downward 
through one in- 
ternode before 
joining another, 
and in any inter- 
node all the bun- 
dles are derived 
from the leaves at 
its summit. 

In Fig. 315. 
with a similar ar- 
rangement in the 
main, there are- 
some complica- 
tions. The lateral 
leaf-bundles [h, c 
in the lower inter- 
node, and g, h in 
the next one) pass 
downward to the 
next node, where 
they unite with 
other descending 
bundles ; and the 
median bundles, 
«,/, I, 0, r, u, pass, 
down through two 
internodes, and 
then fork right 
and left, and 
unite with other 
descending bun- 
dles. Thus in 
least three leaves. 




Fig. 315.— Diagram showing the arrangement of 
fibro-vascular bundles in the stem of Lathyrus Pseuda- 
phaca. The bundles nearest the observer are figured dark- 
er, those farthest away lighter.— After Nageli, 



any internode there are bundles from at 

This is shown in the cross-section of the next to the lower 

internode (Fig. 316), in which the bundles li, f, g, Ic, i pass 



TISSUES OF ANOIOSPERMS. 



441 




Fig. 316. — Cross-sec- 
tion of the next to the 
lower internode of Fig. 
3l5,showingthe arrange- 
ment of the bundles, the 
lettering as in Fig. 315. 
—After Nageli. 



into the second leaf — i.e., the leaf at the summit of the in- 
ternode under consideration ; the bundles 
/, 7n, 11 descend from the leaf next above, 
andj9 and q from the one still higher. 

541. — We may get a clearer idea of the 
mutual relations of the bundles if we con- 
ceive the bundle-cylinder to be split down 
on one side, and spread out upon a plane. 
In Fig. 317 we have such a diagrammatic 
representation of the arrangement of the 
bundles in the stem of Stachys angusti- 
folius. Here each leaf sends down two 
bundles, which pass through two internodes and then unite 

Avith other descending bundles at 
their middle points. The fibro- 
vascular cylinder is thus compos- 
ed when complete of repeatedly 
branching bundles. A cross-sec- 
tion (Fig. 318) through the stem 
at some distance above the lower 
leaves in Fig. 317 
shows that each 
internode c o n - 
tains bundles 
from two pairs of 
leaves — i.e., those 
at its summit and 
those at the sum- 
mit of the one 
above. In Fig. 
318 the pairs of 
bundles marked c and d descend 
from the leaves c and d, while 
those marked e and/ pass down 
from the leayes one internode 

Fig. 317.— Diagram showing the ar- higher up. 
rangement of the flbro-vascular bun- t • -i i l ^ t t 

dies in stachys angustifoiius. a, b, In a Similarly Constructed dia- 
ftom%hi5h'tlie^'suc7essfvi^pa^i?rof gi'am of the fibro-vascular cylin- 

leavesspring.-AfterNageli. ^^^ ^f j^^^-^ ^^^^^ ^Ylg. 319, 

projected upon a series of transverse and vertical lines to 





Fig. 318. — Cross- 
section of the next 
to the lower inter- 
node in Fig. 317, 
showing the disposi- 
tion of the bundles, 
the lettering as in 
Fig. 317.— After Nii- 
geli. 



442 



BOTANY. 



indicate the nodes and the vertical ranks of leaves) the sin- 
gle bundles which descend from the leaves are shown to pass 
through from ten to twelve internodes before uniting with 




Fig. 319.— Diagram showing the arrangement of the flbro-vascular bundles in 2S 
internodes of the stem of Iberis «mara.— After Nageli. 

other bundles. It is seen, moreover, that there are running 
through the stem five series of branching bundles, which are 
not quite vertical, but slightly spiral. In Fig. 320 is shown 
the appearance of an actual section of the stem taken be- 



TISSUES OF ANGIOSPERMS 



443 




Fig. 320.— Cross-section of 
the stem of wliich Pig. 319 
is the diagram, talten above 
the fifth leaf .—After Nageli. 



tweon the fifth and sixth leaves of the preceding figure. The 
bundles are numbered as in Fig. 319. 

542. — In a comparatively small number of instances there 
are fibro-vascular bundles in the stem which have no connec- 
tion with the leaves. These are known as cauline bundles. 

543. — In the Monocotyledons and 
many herbaceous Dicotyledons, the 
libro-vascular bundles ai"e closed — that 
is, there is no zone of meristem tissue 
left between the xylem and phloem after 
these have passed over into permanent 
tissues. There is, as a consequence, a 
definite jDcriod of growth for the bun- 
dles, and when any bundle has fully 
formed all its tissues, no further devel- 
opment can take place in it. This gen- 
erally results in definitely limiting the growth of the inter- 
nodes, and in consequence such plants are as a rule short- 
lived. The perennial woody-stemmed Dicotyledons, and 
some of the herbaceous annuals, possess bundles which are 
open — that is, there is left between the xylem and the phloem 

a zone of meristem tissue which 
continues to grow long after the 
other parts of the bundle have 
passed over into permanent tis-s 
sues. Plants Avith such bundles 
may live and continue to grow for 
an indefinite time. 

544. — A cross-section 'of the 
stem of a Palm (Fig. 321) shows 
it to be composed of parenchyma- 
tous tissue traversed by myriads 
of fibro-vascular bundles, which 
descend from the crown of leaves. 
Each leaf sends down from its broad insertion numerous 
bundles, which, in a vertical section, are seen first to pass in 
toward the centre of the stem, and then to curve downward 
and finally outward. The centre of the stem is thus softer 
than the peripheral portion, as in the latter the descending 




Fig. .321. — Cross-section of the 
stem of a palm, ec, cortical zone ; 
Ig, the softer interior portion of the 
stem ; Ic/'^ the harder peripheral 
portion.— After Duchartre. 



444 



BOTANY 



bundles are more numerous. In such a stem it is evident 
that there can be no considerable increase in thickness after 
it is once formed, and we consequently find that palms 
take a longtime for the formation of a broad bud or growing- 
point {liunctuin vegetationis), and afterward push up a cylin- 
drical stem in which little change subsequently takes j^lace. 

In the Dragon trees 
{Draccena, sp.) and 
some other Monoco- 
tyledons, there is a 
thick layer of paren- 
chymatous cortex be- 
tween the column of 
fibro-vascular bundles 
and the ejoidermis 
(Fig. 322, r), and in 
the deeper layers of 
this a persistent meri- 
stem tissue is found 
(Fig. 322, x). In this 
meristem there are 
formed fibro-vascular 
bundles, which lie par- 
allel to those already 
formed, and in this 
way the stem slowly 
increases in thickness. 
545. — In those Di- 
cotyledons whose 
stems increase in 
thickness there always 
develops soon a layer 
of meristem tissue, 
of one fibro-vascular 




Fig. 322 — Cross-section of Ftem of Draccena. e, 
epidermis ; k. cork ; r, cortex ; 6, a fibro vascular 
bundle bending out to a leaf ; m, parei chyma of the 
fundamental system ; g, gr, fibro-vascular iiuudles ; 
a?, meristem zone of the fundamental system in 
which new bundles and tissues are forming, — After 
Sachs. 



which connects the cambium layer 
bundle with that of the other (Fig. 323). This is made 
easier from the fact that in most (but not all) Dicotyle- 
dons the bundles lie at nearly the same depth beneath the 
epidermis on all sides of the stem, thus forming a cylinder, 
or in cross-section, a ring, as in Fig. 323. Both the fascicu' 



TISSUES OF AN0I0SPEBM8. 



445 





Fig. 323.— Diagramg of dicotyledonous stems as seen in cross-section. B, the cor- 
tical, M, the medullary portion of the fundamental system ; p, the phloem ; x, the 
xylem ; b, b, b, groups of bast fibres ; fc, the fascicular, ic, the interfascicular cam- 
bium.— After Sachs. 




Fig. 324.— Cross-section through a young internode of Sambucus nigra. P, P, cor, 
ticai parenchyma ; p, p, parenchyma of the pith ; between r — r and P—P, sieve tis, 
sue ; g, g, pitted vessels; s, s, and above, spiral vessels ; c — c, the cambium zone, x 
220 —After De Bary 



446 



BOTANY. 





lar and interfascicular cambium layers are composed of 
elongated cells, which multiply by fission in a tangential di- 
rection, and thus give rise to radiating rows of cells (Figs. 
324 and 325). In a tangential section the cambium cells 
present an elongated outline, and their extremities are 
usually more or less oblique (Fig. 326). From these cells 
there develop various tissues. Thus^ on the one side, the 
phloem parenchyma, sieve and fibrous tissues may be pro- 
duced by more or less great modifications (Fig. 327). On 
^^ /• , the other side (the xylem side) new ves- 

sels, fibres, and parenchyma are also devel- 
oped (Fig. 328). The development of 
IP= — ^: these tissues begins in the inner and outer 

(____3^ layers of the cambium, and advances to- 

ward the central layers. It never hajJ- 
pens, however, that all the cambium lay- 
v,;:^^— XV ers pass over into permanent tissues, there 

I ^r always remaining one or a few meristem 

' ^ layers. 

546.— A study of Figs. 326-328 will 
show the probable mode of development of 
the permanent tissues from the meristem 
tissue of the cambium. It is evident from 
a comparison of Figs. 326 and 327 that 
the phloem parenchyma is produced by 
the formation of several transverse parti- 
tions in each cambium cell, and it is prob- 
able that in many cases there is a direct^ 
conversion of cambium cells into sieve 
tubes. That the cambium cells may be 
converted directly into tracheides is evident from Fig. 326, 
and also Fig. 75 (p. 84). In Fig. 328 it is plain that the 
fibrous tissue {If) and tracheides {t) have the same origin, 
and the indications are that even the large pitted vessels 
{gg) are formed from cambium cells by the great increase 
in the diameter of the latter, the thickening of their vertical 
walls, and the partial or complete absorption of their trans- 
verse wfills. The origin of the xylem parenchyma from cam- 




Fig. 325.— The row of 
cells marked a? — a? in 
Fig. 324 ; r. phloem : h, 
xylem ; ati are seen the 
fissions of the cambium 
cells. X 600. — After 
De Bary. 



TISSUES OF ANaiOSPERMS. 



447 



bium cells by the formation of transverse partitions is very- 
clear in this figure. 

547. — In the trees and shrubs of cold climates, or of 
those in which there is one annual period of growth, fol- 
lowed by a period of rest or the cessation of growth, the 





Fig. 326. 



Fig. 327. 



Pig, 326. A tangential section of the cambium region of Cytisus Lahurnvmi. a, 6, 
c, d, cambium cells enclosing the section of a medullary ray ; h, fi, tracheides belong- 
ing to the xylem. x 145.— After De Bary. 

Fig. 327.— Tangential section of the inner phloem region of the same stem as Fig. 
326. s, s,.s, sieve vessels ; m. section of a small medullary ray ; the remaining parts 
of the figure are phloem parenchyma, x 145.— After De Bary. 



processes described above take place each year, giving rise 
thus to an annual layer of xylem (wood) outside of the pre- 
viously formed xylem cylinder, and an annual layer of 
phloem (bark) inside of the phloem cylinder. In the wood 
these layers are generally quite well marked, and in cold 
climates they enable us to determine with accuracy the age 



448 



BOTANY. 



of trees and shrubs (Fig. 329). The layers of the bark are 
rarely well marked, and they generally become soon obliter- 
ated by irregular corky growths in the substance of the bark 




Fig. 328.— Tangential section of the stem of Aifanthus glnndulosvs, through the 
secondary xylem g,q, pitted ^e-'=els ; p,p. xjlcm paienchMua , st, st medullary 
rayain cross section , If, fibrous tibsue vvvuod cellt) ; #, tracheidei?. Highlj magnified. 
—After Sachs. 

itself. They are, moreover, ruptured by the increase in the 
diameter of the woody cylinder, and soon decay and fall 
away. It thus happens that while the annual layers of the 
wood are constantly increasing in number, reaching in ex- 



TISSUES OF ANGIOSPERMS. 



^^^ 



treme cases more than a thousand,* the bark rarely shows 
more than a few distinct layers, and its thickness is generally 
very much less than that of the former. 

From what has been said it is seen that a dicotyledonous stem several 
years old is composed of a series of larger and larger continuous woody 
shells (Fig. B30, 1, 2, 3, 4, 5) surrounded by a corresponding series of 
bark shells, which are smaller and smaller (Fig. 330, 5', 4' 3', 3', 10- 

548.— The Medullary Rays. In the young dico;]/ledonous 
stems there are thick masses of parenchyma, which connect 
the cortical with the medullary (pith) portion of the funda- 
mental system of tissues (Fig. 323). However, as the fibro- 
vascular bundles increase, 
these masses become thin- 
ner, until they are mere 
plates, often not more than 
one or two, or at most a 
few cells in thickness (Figs. 
326-7-8). From their ap- 
pearance and position they 
have long borne the name 
of Medullary Rays. In 
the young stem their cells 
may be parenchymatous, 
but in older ones they are 
frequently sclerenchyma- 
tous. Viewed in a radial 
section of the stem, they are generally seen to be elongated 
in the direction of the radius, having the outlines of right- 
angled quadrilaterals. In the increase of the diameter of the 
stem there is always an increase in the length of the medul- 
lary rays, both in their bark and wood portions ; and when 
from their divergence a considerable space intervenes between 
two rays, one or more new ones arise between them ; thus 
while there may be no more than four or five rays in the 
young plant, it may when old have hundreds of them m its 
circumference (Fig. 329). 

What has been said of the tissues of the Angiosperms must suflBce to 




Fig. 829.— Cross-section of the stem of an 
oak (Quercun E"bnr) thirty-seven years old. 
m, pith ; Ig. heart-wood ; lg\ sap-wood ; rm, 
mednllary rays ; ec, the bark. Much reduced. 
—After Duchartre. 



* In the Lime (Tilia Europma) 107G and 1147, and in the 0'dk.SQ,uer- 
eus Robur) 1080 and 1500, according to De Candolle. 



450 



BOTANY. 




123 4 5W3'2' 



introduce the student to tlieii 
study. For further details, 
he is referred to De Bary's 
admirable treatise, " Ver- 
gleicbende Anatomie der 
Vetjetationsorgane der Phan- 
erogamen und. Fame," in 
which copious references are 
given. The publications of 
Russow will also be found to 
be of great value to the stu- 
dent, 

549. — The systematic 
arrangement of the An- 
giosperms is by no means 
settled. The one mostly 
followed in England and 
this country is a modifi- 
cation of De Candolle's 
system (a.d. 1813), 
which was itself a modi- 
fication of Jussieu's (a.d. 
1789), which in turn was 
based upon the general 
system proposed by Eay 
(a.d. 1703). In the 
'^Genera Plantarum,'' 
(completed 1 888) by Ben- 
tham and Hooker, and 
in the English edition of 
Le Maout and Decaisne's 
" General System of Bot- 

ll any," we have the most 
recent modifications of 
the Candollean system. 
On the continent of Eu- 
rope other systems have 
been used more or less, 
it is probable that 
^- among these are to be 

.^i^ found the best groupmgs 
W3 of Angiosperms to indi- 



r and 



MONOCOTYLEDONES. 



451 



cate their real affinities. Unfortunately for ns, howeverj 
none of our systematic manuals follow any of the Continen- 
tal systems ; we are compelled, therefore, to use for the pres- 
ent the prevailing form of the Canclollean system. In this 
book the sequence of the groups is the reverse of that in 
most American and English books, in order to bring tlie ar- 
rangement of Angiosperms into harmony with that of the 
rest of the vegetable kingdom. 



Sub-Class I. Moi^ocotyledon-es. 

[Endogencs of De Candolle.*) 

550. — ^In these plants the first leaves of the embryo are 

alternate, hence we say 
that they have one cotyle- 
don. The venation of the 
leaves is for the most part 
such that the veins run 
more or less parallel to 
one another, and when 
they anastomose enclose 
four-sided areolsG ; rarely, 
however, their veins are 
irregularly distributed, 
and they anastomose so as 
to form an irregular net- 
work. 




Fig. 331.— Longitudinal section of the seed 
of Indian coirn (Zea Mais), c, adlaerent wall 
of tlie ovary ; n, remains of the style ; fs, 
base of the ovary ; all the remainder of the 
figure is the true seed ; eg, ew, endosperm ; 
fie- — s,§, cotyledon of embryo; e, its epider- 
mis ; k, plumule ; w (below), the main root ; 
ws, the root-sheath ; w (alcove), adventitious 
roots springing from the first iuternodeof the 
btem. X 6.— After Sachs. 

lias its broad dorsal surface in contact 



The germination of Monoco- 
tyledons may be illustrated by 
a couple of examples. In tlie 
seed of the Indian corn the 
embryo lies partly imbedded 
in one side of the large endo- 
sperm (Fig. 331). The first leaf 
of the young plant (the cotyle- 
don or scutellum, Fig. 381, »c 
with the endosperm ; anteriorly 



* From the Greek ev()ov, within, and yevetv, to bring forth. The 
name was given under the false impression that these plants were 
*' inside growers," and the Dicotyledons " outside growers." 



452 



BOTANY. 



i^E 




Fig. 332. 



Pig. 332.— Germination of Indian corn. /., //., 77/., 
successive stages. A and i?, front and side views of 
a fcparatud embryo. In the figures, w, tlie primary 
root ; ws, its root-sheath ; w', w'\ adventitious roots ; 
w'", lateral roots sprinf?ing frotn the main root ; e, 
part of seed filled \\\i\x endosperm ; sc, cotyledon : r, 
its open margins ; k, the plumule ; ^>, b', l>", leaves of 
young plant ; L fragment of wall of ovary. Natural 
size.— After Sachs. 

Fig. 333.— Germination of the Date {Phmnix dacty- 
lifera). 7, transverse section of seed ; c. embryo ; 6, 
endosperm. 77, 777, t^ections of germinating seeds; 
c, apex of cotyledon developing into an absorbing or- 
gan ; st, stalk of cotyledon ; s, sheath of cotyledon ; 
b', b", leaves ; w. root ; w', lateral roots : /?, root-cap. 
7r, young plant, natural size, the lettering a& in 7/7 
A. section of IV at x — x,; B, section at x — y. the 
lettering as in 777 C, sect'~n at c — s, the lettering as 
in 777— After Sachs. 



0LUMALE8. 453 

It is curved entirely around tlie remainder of the embryo. Under prop- 
er conditions the main root pushes through the root sheath {ws, Figs. 
831, 332). The plumule, consisting of a minute stem and a few rudi- 
mentary leaves, next pushes out through the upper end of the curved 
cotyledon {II., Fig. 332). The cotyledon remains in contact with the 
endosperm and absorbs nourishuient (rom it for the sustenance of the 
growing parts. Lateral roots soon appear upon the main root, and 
adventitious ones arise from tho first internodes of the stem (w)''", w", w\ 
Fig. 332). The first leaf above the cotyledon is quite small (6), and 
each succeeding one becomes larger and larger until the full size is 
reached. 

In the Date the small embryo lies imbedded transversely in the large 
endosperm. In germination the cotyledon elongates and carries the 
enclosed root and plumule outside of the seed (//. and III., Fig. 333). 
The apex of the cotyledon (c) expands into an organ through which 
the dissolving endosperm is absorbed. The root pushes downward, 
and soon develops lateral roots {w^). The plumule grows upward, es- 
caping from the enclosing cotyledon, as shown in IV., Fig. 333. The 
first leaves above the cotyledon are here, as in the Indian corn, mucli 
less perfectly developed than the later ones. 

551. — The sub-class Monocotyledones contains about fifty 
natural orders of plants, which are grouped into fifteen co- 
horts. Of these only a few need be noticed. 

552.— Cohort I. Glumales. Grass-like plants with the 
flowers in the axils of scales, which are arranged in spike- 
lets ; the stamens are from one to three, rarely more ; the 
single ovary contains but one ovule, and 'these at maturity 
are completely coalesced, forming a caryopsis. 

Order Gramineae. — The Grass Family. Herbaceous or rarely 
woody plants, with round, jointed, and mostly hollow stems, bearing 
alternate two-ranked leaves with split sheaths. (Figs. 334-9.) 

This very natural order contains about 4500 species, which are dis- 
tributed in all climates. In the tropics they are large and almost tree- 
like (Bamboo) ; in the temperate climates they cover the ground with 
a close mat, while in the colder countries they grow in bunches. Very 
many of the species are valuable on account of their starchy seeds or 
nutritious herbage. None are poisonous (with possibly one or two ex- 
ceptions). 

Triticum vulgare, Wheat, a native probably of Southwestern Asia, 
has been under cultivation in temperate climates for several thousand 
years. Remains of wheat grains have been found in the ruins of the 
lake dwellings in Switzerland, proving that it was cultivated in Europe 
in prehistoric times. By long culture it has formed many varieties ; 



4r>4- 



BOTANY. 



some of tliese are liardy (winter wheats), others are tender (spring 
wheats) ; some are awned, others awnless ; in some the grains are 

Figs. 334-9.— Inplouescknce of tue Oat. 




Fig. 337. 



Fig. 338. 

Fig. 339. 
Fig. 334.— Spikelet. 

Fig. 335.— Spikelet opened. G, glumes ; P, palets ; A, awn ; F^ abortive flower. 
Pig, 336. —Flower with upper palet. 
Fig. 337.— Embryo. 
Fig. 338.— Section of grain. 
Fig. 339.— Diagram of spikelet. Gl, glumes ; 5, palets ; J., abortive flower. 



dark in color (red wheats), in others they are light colored (white 
'Wheats). Fabre's experinaents about a quarter of a century^go appear 
to indicate that wheat was originally derived from a wild grass called 



QL U MALES. 



455 



ovata. From it, in tlie course of from ten to twelve years, lie 
succeeded in producinor the form known as cultivated wheat. (See 
Oardener's Ghronicle, July, 1852.) 

Becale cereale. Rye, is probably a native of Southeastern Europe and 
Southwestern Asia. It has been cultivated for ages and is still much 
grown in temperate climates. 

Hordeum vulgar e, Barley, A native probably of the same region as 
Rye ; has also been long under cultivation. One or two other species 
are also grown. 

Avena saliva, the Oat, was formerly much used as food for man 
especially in cool climates, where it succeeds best. It is now less used. 
Its native country is not certainly known, but it was probably northern 
Europe or Asia. 

Oryz'i sativa. Rice, has been long under culture in Southeastern 
Asia, of which country it was probably a native. It is now cultivated 
also in Egypt, Italy, Brazil, and the Southern 
United States. It furnishes food to more human 
beings than any other single plant. 

Zea Mais, Maize or Indian Corn, a native of 
the warmer parts of the New World, was culti- 
vated by the aborigines of both North and South 
America before the advent of Europeans. It is 
one of the most valuable of the cereals, and is 
now cultivated almost all over the world. Of its 
numberless varieties the larger are grown in the 
hotter, and the smaller in the cooler climates. 

The more important forage grasses are the fol- 
lowing : 

Pldeum pratense, Timothy or Herd's Grass, a native of Europe is val- 
uable on rich soils. 

Agrostis vulgaris, Red-top, a native of Europe, grows well on moist 
soils. 

Dactylis glomerata. Orchard Grass, a native of Europe, is valuable 
because of its growing well in the shade, and so furnishing hay and 
pasture in orchards and woodlands. 

Poa pratensis, Kentucky Blue Grass, a native of the Eastern United 
States and of Europe, is in the latitude of Kentucky the best of all our 
pasture grasses. In drier regions it is small and harsh. 

Mulilenhergia glomerata and M. Mexicana constitute the *' Fine 
Slough Grass " of the Mississippi valley prairies. They furnish val- 
uable hay. 

Several species furnish sugar : 

Saccharum qfficinarum. Sugar Cane, a native of the warmer parts of 
Asia, is a large plant somewhat resembling Indian corn in size and ap- 
pearance. From its sweet juice most of the sugar and molasses of com- 




Fig. 340.— Diagram ot 
hexandrous flower of 
Eice. 



<i56 



BOTANY. 



nierce are made„ It is cultivated extensively in the Southern United 
States, Cuba, Brazil, and, in fact, in all warm countries of the world. 

Figs. 341-4.— Illustrations of Carex. 




Fig. 342. 



Fig. 343. 



Fig. 344. 



Fig. 341. — Underground stem, sending up leafy and flowering stems. 
Fig. 342.— Male flower. Magnified. 
Fig. 343.— Female flower. Magnified. 
Fig. 344.— Section of seed. Magnified. 



It is a curious fact that while the annual production of cane sugar in 
the world is now about 4,000,000 000 pounds, yet five hundred 



LILIALE8 457 

years aero it was but little known to our European ancestors, and even 
a century and a half ago it was one of the luxuries. (Sinimonds.) 

Sorghum vulgare, Chinese Sugar Cane, a native of India, has witliin a 
few years been brought into cultivation in the United States for its 
sweet juice, from which molasses and sugar are made. One variety of 
this species is the Broom Corn, used in the manufacture of brooms. 

Several species of ^oxahoo {Bambusa, sp.) growing in India become so 
large as to supply materials for building the houses of the natives. 

B. arundinacea sometimes attains the height of 30 metres (100 ft.). 
Its uses are almost innumerable. 

Order Cyperaceae. — The Sedge Family. Herbaceous plants, with 
three-angled solid stems, bearing alternate three-ranked leaves, with 
entire sheaths. (Figs. 341-4.) 

There are about two thousand species of sedges, which are distrib- 
uted throughout the world. They grow in tufts, never forming a con- 
tinuous mat, and generally prefer wet localities. They are of little 
value to man, and their stems contain so little nutritious matter that 
they are eaten only to a limited extent by animals. 

Cyjperus esculentus, the Chufa, a native of the Mediterranean region, 
is somewhat cultivated for its small, sweet-tasting tubers. 

Cyperus textilis is used in India for making ropes and mats ; in Egypt 
other species are used for the same purpose. 

Papyrus antiquorum,. Papyrus, is a tall growing plant with stems 2-3 
cm. (1 inch) in diameter. It is a native of Egypt and the adjacent 
countries, and from it the inhabitants anciently made paper by slicing 
its cellular pith, and afterward hammering and smoothing it. 

553. Cohort II. Restiales. — This includes three orders of 
mostly tropical plants bearing glumaceous flowers. 

Orders Restiaceae, Eriocaulonaceae, and Flag-ellarieee. 

554. Cohort III. Commelynales. — Plants with a hexa- 
merous perianth, in two whorls, the inner colored and petal- 
oid. 

Orders Mayaceae, Xyridacese, and Commelynacese. 

The latter contains the well-known Spiderwort Tradescantia, sp.). 

555. Cohort IV. Pontederales. — Marsh plants with a 
gamophyllous petaloid perianth. 

Orders Philydrese, Pontederiaceee, and Rapateee. 

556. Cohort V. Liliales. — Plants with a hexamerous 
(rarely tetramerous) perianth, the parts united or free, and 
usually petaloid. 

Order Juncaceee. — The Rushes. Natives of temperate and cold 



458 



BOTANY. 



climates. The leaves and stems are woven into matting and cLaJr 
bottoms, and the pith is used for the wicks of candles (rush-lights). 

Order Liliaceae.— The Lily Family. Perennial, mostly herbaceous 
plants, with entire leaves, and generally showy flowers. The species, 
of which there are about two thousand, are distriljuted in all climates. 
Some of these are valuable as food, others furnish useful medicines, 
while many are among our finest ornamental plants. 

The more important food plants are the following : 

Allium Cepa, the Onion, a native probably of the Mediterranean re- 
gion, is grown throughout the world. 

Allium Porrum, the Leek, A. sativum, Garlic, A. ascalonicum, 

Figs. 345-8.— Illustrations of Fritillabia. 




Fig. 345. Fig. 347. iiG. 348. 

Fig. 345.— Section of flower. 
Fig. 346.— Flower diagram. 
Fig. 347.— Section of ovary. 
Fig. 348.— 0\-ule. 

Shallot, and a few other species, all natives of the Old World, are con. 
siderably used. 

Asparagus officinalis, Asparagus, is a native of the Atlantic and 
Mediterranean coasts of Europe, and of the sandy plains of Central and 
Western Asia. It has been cultivated in England for upwards of two 
thousand years, but it is an interesting fact that in all that time it has 
exhibited very little variation. 

Among the medicinal plants may be mentioned 

Aloe vulgaris, of the Mediterranean region, and other species in 



LILIALES. 



459 



Southern and Eastern Africa, tlie inspissated juice of wliose leaves con- 
stitutes tlie drug Aloes. 

Smilax officinalis, of South. America, and other species, furnish Sarsa. 
parilla root. 




Fig. 349.— Underground parts of Colchicum aittumnale at the time of flowering, 
,A, front view ; k, old corm ; s', s", scales surrounding flower stalk. B, section show- 
ing new stem, W, with nidimetitary leaves. V, I" ; the very long tubular flowers, b, b\ 
spring from near the summit ot the new stem, h\ I'he following spring A' will elon- 
gate and carry the fruit, and leaves l\ I", above ground ; ttie lower part of W will en 
large into a corm like k', while at Tc" a new plant will form as a lateral bud,— After 
Sachs. 



\ 



Scilla maritima ; the sliced buib of this Mediterranean sand plant is 
the druo- Squill. 

Verat'""""' album, the White Hellebore of the mountains of Central 



iGO BOTANY. 

Europe, and V. mride. Green Hellebore of tlie Eastern United States. 
are poisonous emetics. The rbizome is officinal. 
Ornamental plants : 

Asphodelus luttus is the Asphodel of Southern Europe. 
Agapanthus wnbellatus, the Love Flower of the Cape of Good Hope, 
is a beautiful greenhouse plant, bearing pale blue flowers. 

Golchicum autumnale, the " Meadow Saflfron " or "Autumn Crocus" 
of Europe, is curious for its producing leaves in the spring, and then, 
long after these have died down, in the autumn sendintr up one or two 
long-tubed pale flowers, which soon wither away ; the following spring, 
by the lengthening of the underground stem, the seed-pod is carried 
up, along with the green leaves (Fig. 349). The corms of tliis pl^nt 
were formerly in some repute as medicines, 

GoiiTiallaria majalis^ the Lily of the Valley, is a native of woodlands 
and shady places in England, Europe, and Siberia. 

Dracmna Draco, the Dragon Tree of Western Africa and the adja- 
cent islands, is cultivated as a curiosity in green-houses. A tree of 
this species on the island of Teneriffe was, at the time of its destruc- 
tion by a hurricane in 1867, upwards of 20 metres (70 ft.) liigb, and 5 
metres (16 ft.) in diameter, and from its known slow growth it must 
liave been many hundreds, possibly some thousands, of years old. 

FritillaTVi imperidis, the Crown Imperial, a native of the south of 
Europe and Western Asia, is a showy plant. 

Funkia, sp., and HemerocalUs, sp., the Day Lilies, the former from 
China and Japan, the latter from Southern Europe, and Ilyacinthus 
orientalis, the Hyacinth of Asia Minor, are in common cultivation. 

Lilium — many species. The True Lilies. Aside from our native 
species, L. Philadel'pMcuin, L. Canadense, and L. superhum, which 
deserve cultivation, the following are rommonly found in gardens : 
L. hulhiferum, the Orange Lily, from Southern Europe : flowers 

orange. 
L. tigrinum, the Tiger Lily, from China ; flowers orange-red. 
Jj. Pomponium, the Turban Lily, from Europe ; flowers red. 
L. Chalcedonicum, the Red Lily, from Asia Minor ; flowers red. 
L. MarPigon, the Turk's Cap Lily, from Europe ; flowers flesh- 
colored. 
L. speciosum, the Showy Lily, from Japan ; flowers rose-colored. 
L. auratum, the Golden Lily, from Japan ; flowers white and 

golden. 
L. candidum. the White Lily, from Asia Minor ; flowers white. 
L. Japonicum, the Japan Lily, from Japan ; flowers white. 
L. longijlorum, the Long flowered Lily, from Japan ; flowers 
white. 
Myrsiphyllum asparagoides, a delicate climber from the Cape of Good 
Hope, is grown in windows and conservatories under the name of 
;Smilax. 



ABALE8. 4G1 

Ornithogalum umhellatum, tlie Star of Bethlehem, is a native of Cen- 
tral Europe. 

Polianthes tuberosa, the Tuberose, a native probably of the East 
Indies, bears a tall spike of fragrant white flowers. It is sometimes 
placed in the order Ainaryllidaceae, 

Ruscus aculeatus, the Butcher's Broom of England and Southern 
Europe, a curious shrub, with flat leaf-like branches, is rarely cultivated 
with us. 

Tritoma uvaria, of the Cape of Good Hope, bears a tall spike of red 
flowers, and hence receives in cultivation the name of the '* Red-Hot 
Poker Plant." 

Tulipa Oesneriana, the Tulip, is a native of the Levant. It was 
brought into Europe about three hundred years ago, and originally 
bore yellow flowers, but under long culture it has developed number- 
less varieties. To the Dutcli we owe much of the improvement in this 
flower ; in the first half of the seventeenth century throughout Holland 
so much attention was given to its culture, and such high prices paid 
for single bulbs of the finer varieties, that a speculative mania (known 
aa the " tulipomania") arose, resembling the wildest of modern grain 
or stock manias. 

Yucca, of several species, known by the name of Adam's Needle, 
Spanish Bayonet, Bear Grass, etc., is a genus of fine ornamental 
plants, natives of the warmer parts of America. The strong fibres are 
sometimes made into cordage. The roots contain saponin, and are 
used by the Mexicans instead of soap for washing. 

Xanthorrh(£a includes the curious Grass Gum Trees of Australia. 

557.— Cohort VI. Arales.— A group of dissimilar plants, 
some being large trees, and others microscopic floating herbs. 

Order Lemnaceee.— The Duckweeds. These smallest of Phanero- 
gams consist of floating disks (thalli), with no distinction of leaf and 
stem, bearing one or several roots beneath (in Wolffia, however, no 
roots). They are parenchymatous throughout, or with only rudiment- 
ary vascular tissues. Their flower-clusters are sunken into pits in the 
top or edge of the disks, and consist of one or two stamens and a single 
pistil, representing as many reduced flowers. There are about twenty 
species, widely distributed throughout the northern hemisphere. We 
have eight or ten species in the United States. (Figs. 350-2.) 

Order Aroideae.— The Arum Family. Herbs often large and palm- 
like in appearance, with large leaves having reticulated venation. In- 
florescence generally surrounded by a spathe. Of the Aroids then^ are 
about 1000 species, distributed mostly in tropical countries, where they 
sometimes attain a height of several metres (6-12 feet) ,• in temperate 
climates they are much smaller. They possess an acrid juice, which 
may be poisonous. 



402 



BOTANY. 



Some of tlie species have been used in medicine, among wliicli are 
the Indian 'Vuvni^ {Aris(p.ma), and Sweet Flag {Acorus). 

Galocasia cmtiquorum, a large plant of the tropics, is there grown for 
its fleshy farinaceous corm. It is grown with us for its fine foliage. 

Richardia Afiicana, the so-called Calla-lily, or Ethiopian Lily, a na- 
tive of the Cape of Good Hope, is a common green-house plant. 

Symplocarpus fmtidus, the Skunk-cabbage of the Northern United 
States, is remarkable for the mephitic odor of its bruised leaves. 

Amorphophallus 2\tanum, an Aroid discovered in 1878 by Beccari in 

Figs. 350-S.— Illustrations of Leuna. 






Fig. 350. 



Fig. 351. 



Fig. 352. 



Fig. 350.— Two plants of L. minor. Magnified. 
Fig. 351.— Three flowers in a spathe. 
Fig. 352.— Section of pistil. 

Sumatra, has an enormous spathe, 1.7 metres (6 feet) in depth, and 83 
cm. (2|- feet) in diameter. 

Order Typhaceae, represented by tlie two genera Typlia and Spar- 
ganium. 

Order Pandanaceae. — Mostly tropical plants, some of them of a 
tree-like aspect. 

Pandanus Includes the Screw Pines of the East Indies, so called from 
the spiral arrangement of their clustered leaves. 

Carludomca pcdmata, a Central American plant, with palmate radical 
leaves borne on petioles three metres (8-10 feet) long, is important as 
furnishing the material from which the famous Panama hats are 
made. 

558.— Cohort VII. Palmales. —Shrubs or trees with di- 
vided (rarely simple) leaves. Flowers in a spadix. 



PALM ALE'S. 



463- 



Orders Nipaceae and Phytelephasieae, both of the tropics. In 
the latter, Phytelephas macrocarpa, of Central America, is remarkable 
for the ivory-like endosperm in its large seeds ; hence its name of 
Ivory Nut. 

Order Palmacese. — The Palm Family. Trees, shrubs, or woody 
climbers ; natives almost exclusively of the torrid zone, or the adjacent 



Figs. 353-6.— Illustrations of Palmace^ 




Fig. 356. 



Fig. 355. 



Fig. 353.— Fruit of Cocoa-nut. a, exocarp ; 6, endocarp ; c, testa ; d, endosperm ; 
«, embryo ; /, milk cavity. 
Fig. 354.— Cocoa-nut seen from below. 
Fig. 355.— Vertical section of a Date, showing seed inside. 
Fig. 356.— Seed of Date in cross-section, showing embryo. 

hotter portions of the temperate zones, being rarely found beyond 40* 
North and 35° South latitude. The arborescent species are among tlie 
most striking and majestic of plants ; their long cylindricul stems fre- 
quently rise to the height of thirty metres (100 feet), bearing at their 
summits spreading crowns of large leaves, and drooping clusters of fruit. 
The whole number of known species is not far from one thousand. 
The economic value of the Palms is very great ; in fact it may be ques^ 



404 BOTANY. 

tioned whether any other order of plants (the Grasses poBsibly excepted) 
approaches them in the importance of the products they furnish. Every 
species appears to be useful, and the uses of some of the species may 
be reckoned by hundreds. In some countries every want of mau is 
supplied by one or another of the palms. 

/. Tribe Cocoinew, — Atalea iunifira is a Brazilian species of 
stout-growing trees, whose fibrous leaves are used in makin^r ropes, 
mats, and coarse brooms. The nuts, known as Coquilla nuts, are seven 
to eight cm. (3 inches) long, very luird, and are used for making door- 
handles, bell-pulls, etc. 

Cocos nudfeva, the Cocoa-nut Palm, is a native of the coasts of tropi- 
cal Africa, India, Malay, and islands of the Indian and Pacific Oceans. 
It is now, however, cultivated throughout the tropics. Tlie tree varies 
in height from fifteen to thirty metres (50 to 100 feet), and bears long 
pinnate leaves. The nuts, which are borne in clusters of seven to ten 
or more, are the well-known cocoa nuts of commerce. As a new cluster 
is pushed out every month, the annual yield of a single tree may be 
from 100 to 150 or more nuts, and this may continue for forty years. In 
some parts of India and other countries, the white albumen of the nut 
forms nearly the entire food of the natives, and the milk serves them 
for drink. In this country great quantities are used as a delicacy and 
for culinary purposes. 

In cocoa-nut countries the uses of the root, stem, leaves, and fruit are 
said to be as numerous as the days in the year, sufficing for all the wants 
of the inhabitants. The root is used as a masticatory ; the stem is used 
for the most diverse purposes, while the hard case of the base is used 
for making drums, and in the construction of huts, the tender termi- 
nal bud is highly prized as an article of food. The juice of the 
flower-stems is rich in sugar, and this, by fermentation, produces an ex- 
cellent wine, and by distillation yields a spirit called arrack. From the 
sheaths and leaves the natives construct roofs, fences, baskets, buckets, 
ropes, mats, brooms, and numerous other articles. The fibre from the 
leaves and sheaths is imported into this country and made into " coir" 
ropes, floor-matting, brushes, and brooms, and used also for stuffing 
cushions. Even the hard shell is of use in the manufacture of cups 
and ornaments. 

Elms guineensis, of West Africa, produces annually large quantities 
of pulpy fruits, each containing a hard nut. From these palm oil is 
obtained, which is used in Europe and the United States for making 
candles, for the manufacture of soap, and also to some extent for lubri- 
cating purposes. 

II, Tribe Coryphinece, — Copernica cerifera, the Wax Palm of 
Brazil, attains the height of twelve metres (40 feet), with a diameter of 
stem of thirty cm. (1 foot). The hard wood takes a fine polish, and is 
used for veneering. The young leaves are coated with a waxy secre- 
tion which is used in England for making candles. 



PALMALES. 465 

PhcBnix dacfylifera, tlie Date Palm, is a native of Nortliern Africa 
and Western Asia, now naturalized in the south of Europe. The tree 
is dioecious, and grows to the height of ten to twelve metres (40-50 
feet), bearing a crown of leaves, each leaf being four to six metres (15- 
20 feet) long. The fruit is produced in large bunches, containing from 
twenty to thirty dates. Dates constitute a large portion of the food of 
the Arabs of the African and Arabian deserts. They are largely im- 
ported into the United States. They are prepared by gathering before 
they are quite ripe, and then drying in the sun. 

The cultivation of the date palm has for ages been an object of first 
importance in Arabia and Nortliern Africa. The trees are hereditary, 
and are sold as estates, constituting the chief wealth of the inhabi- 
tants. 

Sahal Palmetto the Cabbage Palmetto, S. serrulata, the Saw Palmetto, 
S. Adansonii, the Dwarf Palmetto, and Ghammrops Hystrix, the Blue 
Palmetto, all of the southeastern United States, and Washingtonia jil- 
ifera, of California and Arizona, are our principal native palms. 

III, Tribe Borassinece. — Borassus flabellifoi'mis, the Palmyra 
Palm, is a native of nearly all Southern Asia. It has large fan-shaped 
leaves, anda cylindrical stem rising to the height of fifteen to thirty me- 
tres (50 100 feet). Wine, or toddy, and sugar are made from the juice ; 
the young sprouts of the flowering branches are used for food in the 
same manner as asparagus. From the stem is obtained Palmyra wood. 

Hyphcene thebaica, the Doum or Gringerbread Palm, is a branching 
species of the upper Nile region. It produces fruits of the size of an 
apple and with the flavor of gingerbread. A resin derived from this 
tree is known as Egyptian Bdellium. 

Lodoicea sechellarum, the Double Cocoa-nut of the Seychelle Islands 
in the Indian Ocean, is a giant among the palms. It attains the height 
of thirty metres (100 feet), its stem being forty-flve to sixty cm. (1^ to 2 
feet) in diameter. It produces large oblong nuts, which have the ap- 
pearance of being double, and which weigh from thirty to forty pounds. 
They are borne in bunches of nine or ten in number, so that a whole 
bunch will often weigii 400 pounds. It takes ten years to ripen the 
fruit, the albumen of which is similar to that of the common cocoa-nut, 
but it is too hard and horny to serve as food. The leaves are made into 
hats, baskets, etc. The demand for the leaves for these uses has become 
so great that the trees are cut down in order to obtain them, and as no 
care is taken to form new plantations, it is feared that this palm will 
eventually become extinct. 

IV, Tribe Calamece, — Calamus Motang siud several other spe- 
cies include the Rattan or Cane Palms of India and the Malayan 
Islands. They have slender reed-like stems which grow to a great 
length, often from sixty to one hundred or more metres (200-300 feet), 
and are imported into Europe and the United States for making chair- 
bottom > umbrella-ribs, etc. 



46G BOTANY. 

Calamus Draco, of the same region as the precedinp^, yields a reddish 
resinous substance known as Dragon's 13h)od, and which is a secretion 
coating the surface of the small fruits. Dragon's blood is used for col- 
oring- varnishes and for staining horn, 

Sagus loBvis and S. Rumphii, Sago Palms, are trees nine to fifteen 
metres (30-50 feet) high, natives of Siam, the Indian Archipelago and 
other islands of the East. The sago is obtained by splitting the trunks 
and extracting the soft white pith ; this is thrown into tanks of water, 
in which it is repeatedly washed and strained until a pure pulpy paste 
is obtained. In this state, in order to preserve it, the natives keep it 
under water, and it forms a large proportion of their food. For expor- 
tation it is dried and granulated through sieves. A tree fifteen years 
of age yields from six to eight hundred pounds of this nutritious 
material. 

V, Tribe Arecinece, — Areca Caterhu, the Betel Palm of Cochin 
China and the Malayan peninsula and islands, produces a fruit of the 
size of a hen's egg, which is the famous Betel Nut or Pinang of the far 
East. The nut is cut into pieces and rolled up with lime, gambler, etc., 
in a leaf of the betel pepper, and chewed as tobacco is in this country. 

Garyota urens, of ludda,, \s one of the wine or " Toddy" palms. It 
grows to the height of fifteen to eighteen metres (50-60 feet), and has a 
Inrge crown of compound winged leaves. It is said that this tree will 
yield one hundred pints of toddy in twenty-four hours. 

Geroxylon andicola, the Wax Palm of the mountains of New Granada, 
is a tall tree, bearing large pinnate leaves five to six metres (15-20 feet) 
long. It is found on the mountain sides nearly to the snow line. The 
trunk is coated with a resinous wax, which is scraped off by the natives 
and used for making candles. 

Gham(Edorea of several species, climbing palms of New Granada are 
interesting on account of their stems being used in forming suspension 
bridges. 

Saguerus saccharifer of the Malayan Archipelago is a valuable Sago 
Palm. It is twelve to fifteen metres (40-50 feet) high, and bears enor- 
mous pinnate leaves ; a tree grown in the Kew Gardens bore leaves 
twelve metres (40 feet) in length. Sugar is also obtained from the 
juice which flows from the wounded spadix. 

559. Cohort vni. Potamales. — Mostly herbaceous wa- 
ter plants, with all of the parts of the flower distinct ; the 
embryo large, and endosperm wanting. 

Order Naiadaceae, — The Pond-weeds. 

Order Alismaceae. — The Water Plantain Family. This order is 
interesting from the fact of its evident relationship to the Ranales 
(Cohort 36) among Dicotyledons, as long ago suggested by Adanson, 
and insisted upon by Lindley. (Figs. 357-9.) 



NARCISSALES. 



467 



Alisma and Sagittaria are two common genera^ 

560. Cohort IX. Triurales, with one small and little 
known order. 

Order Triuridese. — Delicate, almost colorless lierbs of the tropics. 

561. Cohort X. Dioscorales. — Climbing herbs or iinder- 
shrubs, bearing reticulately yeined leaves. 

Order Dioscoreaceae. — The Yam Family. Several species of Dios» 
corea produce edible tubers. 

D. saliva, D. aculeata, and otlier species of India are extensively 
grown there and in tlie West Indies as potatoes are grown in cooler 
climates. 

J). Batatas and D. Japonica are known as Chinese Yam*?. 

Testudinaria elephanti'pes, of the Cape of Good Hope, is a curious 



Pigs. 357-9.— Illustrations op Alisma Plantago. 





Fig. 357. Fig. 358. Fi<? «59. 

Fig. 357.— Flower cut vertically. Magnified. 

Fig. 358.— Seed. Magnified. 

Fig. 359.— Section of seed. Magnified. 

green-house plant, having a laro^e, woody, above-ground corm-fitem, 
from which spring every year slender twining steins. 

562. Cohort XI. Nareissales. — Plants with narrow, often 
equitant leaves, having parallel venation ; seeds ^jontaining 
endosperm. 

Order Heemodoracese. — The Blood- wort Family. 

Order Amaryllidaceae. — The Amaryllis Family. Distinguished 
from the next order by havii g six stamens, and leaves which are not 
equitant. The four hundred species are herbs of temperate and trop- 
ical climates ; many possess a narcotic and poisonous principle. 

Agave Americana, the Century Plant of Mexico, is now much grown 
in conservatories, and is said to be naturalized in Soutliein Eurone. in 
California and its native country it blooms at the age of from ten to 



408 BOTANY. 

fifteen years, but in cool climates it requires from thirty to seventy or 
more. The mature plant has a clilster of thick, sharp-pointed radical 
leaves, each about 2 metres (6 ft.) long, fiom the centre of which it 
Sends up a fiowerin<r stem 10-15 cm. (4-6 in.) thicli, and 5-6 metres 
(16-20 ft.) high, bearing hundreds of yellow flowers. The Mexicans 
cut out the central bud just before the lengthening of the flowering 
Btem, and from the juice, which flows out in great abundance, obtain 
by fermentation the drink called " Pulque," or by distillation the more 
generally used " M(^f^cal." The subterranean stems possess a detergent 
principle, and under the name of " Amole " are much used by the 
Mexicans in washing. The strong fibres in the leaves are used for 
cordage. 

Hmmanthns toxicaria, of So-j/^- Africa, has a poisonous bulb, which 
is used by the Hottentots for j.y!c,oning their arrows. 
Many species are grown for the beauty of their flowers ; among these 
may be mentioned : 

Amaryllis, of many species, mostly from South 
Africa and South America. 

Galanthus nivalis, the Snowdrop, of Europe. 
Leucojum vernum, the Snowflake, of Europe. 
Narcissus, of many species ; this includes the 
Daffodil, Jonquil, Polyanthus, etc., all natives of 

Europe. 

Fig. 360. — Flower ^ , _ ., ^, .. , ^ ., _, 

diagram of Irida- Order Iridaceae. — The Ins Family, The sta- 
ceae.— After Sachs. rnens are only three (by the abortion of an inner 
•whorl, Fig. 360), and the leaves are equitant. The order contains five 
hundred species, which are mainly found in the south temperate clim- 
ates, a smaller number occurring in north temperate regions. They 
contain a purgative principle, which has been used in medicine. 

Crocus vernus and other species are commonly grown for their early 
spring flowers ; the dried stigmas of C. sativus constitute the drug Cro- 
cus or Saffron used in medicine and also in dyeing. 

Gladiolus psittacinus and other species, irom the Cape of Good Hope^ 
are deservedly popular as ornamental plants. 

Iris Germanica, of Europe, and many other Old World species, are 
common in gardens. 

Our native /. versicolor, I. cristata, and others, are also worthy of 
culture. 

563. Cohort XII. Taccades. — This includes two small 
tropical orders of herbaceous plants. 

Orders Taccacese and Burmanniacese. 

564. Cohort XIII. Orchidales. — Herbs with a hexamer- 
ous (rarely trimerous) zygomorphic perianth ; the stamens 
and style more or less confluent into a common column, and 




0RCHIDALE8. 



•iG9 



the minute seeds containing a rudimentary embryo and no 
endosperm. 

Order Apostasiaceae, a small order of East Indian plants, wliich are 
interesting because of their 

evident relationship to the B ^-^ ^ -^ 

Orchids, from which they AS^_ / . ^A 

differ in having the style 
partially free from the sta- 
mens. 

Order Orchidacese. — 
The Orchids. Terrestrial 
or epiphytic plants, whose 
stamens and style are com- 
pletely united into a com- 
mon column or gynoste- 
mium. The three thousand 
species are found in "all 
climates and in all situa- 
tions but maritime and 
aquatic." (Hooker.) 

This order has long been 
highly esteemed for the 
many curiously shaped and 
colored flowers it affords, 
and many hundreds of its 
species are to be found in 
cultivation in conservato- 
ries. They are' interesting 
also from the fact that none 
of them are, unaided, capa- 
ble of fertilizing their 
ovules, and appear in every 
case to be dependent upon 
insects for the transport of 
the pollen and its deposition 
upon the stigma. 

This great order is usu- 
ally divided into seven 
tribes, as under. 

Tribe I, Cypripe- 
dieWf with two pollinifer- 
ous stamens containing 
granular pollen (Fig. 362). 

In this the genus Gypri- 
pedium, which contains our native Lady's-Slippers,is the most important. 
Some of the species, notably G. spectabile and G. acaule, are greatly ad- 
mired in cuhivation. 




Fiff. S61.— Orchis maculata. A, a symmetrical 
vertical section of a flower bnd. B, transverse sec- 
tion of tlie bud. 6', transverse section of ovary. 
D, mature flower, with one sepal removed . x, 
axis of dower cluster j &, bract ; s, sepals ; p, pet- 
als ; I, labellum ; sp, its spur ; a and p',, pollen- 
mass ; h, its viscid disc ; gs, the column (tryno- 
stcmiiim); near gs is the stigma which project* 
toward h; f, inferior ovary, twisted in D ; st, sta- 
minodes. — After Sachs. 



470 



BOTANY. 



Tribe IT, Neottiecef with a single dorsal anther, containing 
two or tour soft x)ollen masses attached to a viscid disc. Our principal 
genus is Spiranthes. 

Tribe III, Artthusew, with a single terminal anther, contain- 
ing two or four powdery pollen masses. 

Our native Arethusa and Cal'ipofjoii are fine representatives of this 
tribe. The Vanilla plant ( Vanilla planifolia, and other species) of 
tropical America, a climbing epiphyte, produces fleshy capsules 12 to 
25 cm. (5-10 in.) long, which are highly aromatic, and much used in 
the manufacture of confections, beverages, medicines, etc. When first 
introduced into the East Indies, where it is now much grown, it failed to 

perfect fruit ; artificial p llination hav- 
ing been resorted to, however, the dif- 
culty at once disappeared. (Fig. 803.) 
Tribe IV, Ojjlirt/dew, with a 
single anterior anther, containing two 
stalked pollen masses, each attached to 
a viscid disc (Fig. 361). 

Our pretty little Orchis specfahilis, 
and many species of Habenaria, are 
our principal representatives of this 
tribe. From the tubers of Orchis mas- 
cula and other European and Asiatic 
species, the starchy-mucilaginous and 
highly nutritious substance " Salep," 
4s obtained. 

Tribe V, Vandece, with a single 
terminal or dorsal anther, containing 
waxy pollen masses attached to a vis- 
cid disc. 

We have no native representatives 
of this tribe. Many of the tropical 
species are of wonderful forms; indeed, 
as Mr. Darwin says of them, they are 
" the most remarkable of all Orchids." In some genera they assume 
the most curious forms, resembling insects of various kinds, birds, etc., 
etc. In Catasetum saccatum, a diclinous South American species, 
when certain sensitive parts of the column of the male flower are 
touched by an insect, the pollen masses are by a peculiar contrivance 
thrown out forcibly in such a direction as to strike the insect, to 
which it adheres by a viscid disc, and is thus carried to and brought in 
contact with the stigma of the female flower. 

Tribe VI, Epidendrece, with a single terminal anther, contain- 
ing stalked, waxy pollen masses, these not attached to a viscid disc. To 
this tribe belong in the United States Tipularia, Bletia, and Epiden- 
drum, the latter an epiphyte, occurring only in the Southern States. 




Fig. 362 — Sexual organs of the 
flower of C I prijpedivmx calceol us, the 
perianth,^?, lemoved. A, side view. 
B, back view. C\ front view. /, the 
inferior ovarj"- ; gs, the column or gy- 
nostemium ; aa, stamens ; s, sterile 
stamen or siaminode ; n, stigma. — 
After Sachs. 



AMOMALES. 



471 



Of the exotics, Codogyne, Lcelia^ Cattleya, etc. , are to be seen in conserva- 
tories. 

Tribe VII. MalaocideWf with a single dor- 
sal, terminal, or anterior anther, which contains four 
stalkless, waxy pollen masses, not provided with a 
viscid disc. 

Calypso, Liparis, Corallorhiza, and other genera 

occur in the United States ; the last named appears 

to be parasitic. Among the many exotics may be 

mentioned Bulhophyllum, Dendrohium, Malaxis, 

'////iSP etc. 



Amomales. — Herbs 



565. Cohort XIV. 

(some almost arbores- 
cent) with hexamerous 
and mostly zygomor- 
phic perianth ; sta- 
mens six, generally 
from one to five only 
polliniferous. 

Order Bromeliaceae. 

— The Pine-apple Family. 
Distinguished from the 
next by the regular flow- 
ers and six perfect sta- 
mens. About two hundred 
species of almost entirely 
tropical plants constitute 
this order. But one genus 
{Tillandsia) is represented 
in the Southern United 
States ; of the eight or ten 

native species, the Long Moss {T. usneoides) of the 
Southern Atlantic coast is the best known. It is 
used in upholstery and in the manufacture of mat- 
tresses. 

Ananassa sativa, the Pine-apple, supposed to be 
a native of Brazil, is now cultivated throughout the 
world. In cool climates it is grown in hot-houses, 
and it is said that these are much better than those 
grown out of doors in warm climates. The fleshy 
fruits are aggregated into solid cone-like masses (Fig. 
3G4), the well-known Pine-apples of commerce. 

Order Scitamineee. — The Banana Family, with 
zygomorphic perianth, and one to five, very rarely 
six, perfect stamens. Three sub-orders are well marked. 




Fig. 364. — Spike of the 
fruits of tlie Pine-apple (An- 
anassa sativa) terminated 
by a tuft of leaves. 



Fig, 363.— Eipened 
ovary of Vanilla, Hplit 
op. n and showing the 

si'eds. 



472 



BOTANY. 



Snh-Ovder JMiiscBf with five polliniferous stamens (rarely aix), 
Tlie genus Mufid contains several exceedincjly valuable plants. M. 
sapientum, the Banana, and M. paradisiaca, the Plantain, of the trop. 
ics everywhere, are large herbs, 3-5 metres (10-15 ft.) high, with the 
sheathing petioles of their large leaves forming a tree-like stem. 
Their well-known fruits constitute almost the sole article of food for 
millions of people in the tropics, and are also largely exported to all 
countries. It has been calculated that from twenty-five to sixty-six 
tons of bananas can be grown upon an acre of ground, supplying more 
nourishment to man than is afforded by any other plant. They are 
considerably grown in hot-houses, both as ornaments and for their 




Fig. 365.— Part of a flowering plant of the Banana, showing the unfolding flower- 
bud and the young fruits. 

fruits. From their leaves and petioles a good fibre is obtained, and 
from the allied 31. textilis of the East Indies is obtained " Manilla 
Hemp," so much used in the manufacture of various textile fabrics. 

Strelitzia Beginm, of the Cape of Good Hope, is a common conserva- 
tory plant. 

Sub- Or'der Zingiber CBf yviih one polliniferous stamen, bearing 
a two-celled anther. Several of these tropical plants are important. 

Curcuma longa, of the East Indies and tropical Pacific islands, has 
a yellow colored rhizome, which constitutes the well known dye, 
♦'Turmeric." 

Zingiber officinale, the Ginger Plant, probably a native of India, is 
now grown in most tropical countries for its aromatic rhizomes, which 



DIC0TYLED0NE8. 



473 



prlien dried and powdered constitute the ginger of commerce. That 
from the West Indies, called Jamaica Ginger, is considered the best. 

Sub-Order CannWf with one polliniferous stamen, bearing a 
me-celled anther. Aside from Canna, with its many ornamental spe- 
cies now common in gardens, one other plant deserves mention, viz. : 

Maranta arundinacea, a native of tropical America, now grown ex- 
tensively for its fleshy rhizomes, frorn which a starch known as "Arrow- 
root " is obtained. 

566. Cohort XV. Hydrales. — Small aquatic plants, with 
1 hexamerous regular perianth, and stamens three, six, nine, 
3r twelve. 

Order Hydrocharideae. — This contains the Eel Grass, Vallisneria 
spiralis, and Water Weed, Anacharis Canadensis, 
common in our ponds ; the latter is naturalized in 
England, where it chokes up streams. 

Fossil Monocotyledons. — The earliest Mono- 
jotyledon, so far as known at present, was a Tri- 
issic species of Yuccites, doubtfully referred to the 
Liliacese. In the Jurassic the Graminese, Cyper- 
icese, Liliacese, Naiadacese, and Pandanaceae were 
represented by a tew species. In the Cretaceous the 
.'aunae, Dioscoreacese, and Palmacete appeared. 
A. species of the last-named order has been discov- 
3red in the Cretaceous of Western Kansas. In the Tertiary most of the 
modern orders of Monocotyledons were represented (however, no orders 
3f Cohorts II., III., and XIII. have yet been found). Fifteen species 
Df palms have been described from the Tertiary of the Great Plains 
■md the Rocky Mountain region,* extending as far north as northern 
Dakota and Vancouver's Island. Their remains are also abundant in 
the Tertiary of Mississippi. 




Fig. 366.— Diagram 
of I he flower of Cari- 
na, showing theoreti- 
cal structure. — After 
Sachs. 



Sub-Class II. Dicotylebones. 



{Exogence of De Candolle.f) 

567. — In the plants of this sub-class the first leaves of the 
3mbryo are two and opposite, hence they are said to have 
two cotyledons. The venation of the leaves is for the most 

* "Contributions to the Fossil Flora of the Western Territories. 
Part II. The Tertiary Flora," by Leo Lesquereux. Washington, 1878. 

f From the Greek k^a, outside, and yevetv, to bring forth. The 
name is no longer a proper one, as we now know that these plants 
ire not, strictly speaking, " outside gi'owers ; " on the contrary, they 
increase in thickness by the growth of an internal meristem layer. 



474 



BOTANY. 



part such that the veins rarely are parallel to each other, and 
in their anastomosing they form an irregular net-work. 

The germination of Dicotyledons may be illustrated by a couple of 
examples. In the seed of the Windsor Bean (Fig. 367) the embryo 
entirely fills up the seed-cavity, the endosperm having all been ab- 

FiGS. 367-8.— Germination of Dicotyledons. 




Fig. 368. 



Fig. ZQ7 .— Vicia faba. A, seed with one cotyledon removed ; c, remaining cotyle- 
don ; kn, the plumule w, the radicle ; s, seed-coat. B. germinating seed ; «, seed- 
coat, partly torn away at I; n, the hilum; st^ petiole of one of the cotyledons; ^, 
curved epicot.vledonary stem ; he, short hypccotyledonary stem ; h. main root ; ws, 
its apex ; kn, bud in the axil of one of *the cotyledons. — After Sachs. 

Fig. 368. — Ricinus communis. /., longitudinal section of the ripe seed. //., ger- 
minating Seed with the cotyledons still inside of the seed-coat (shown more distinct- 
ly in A and B). s, seed-coat ; e, endosperm ; c, cotyledon ; he. hypocotylcdonary 
stem ; w, primary root ; w', branches of root ; a?, caruncle, a peculiar appendage to 
the seeds of Euphorbiaceoi.—Mtev Sachs. 



sorbed. The thick cotyledons lie face to face, and are attached below 
to the small stem of the embryo plant. The stem extends upward a 
short distance between the cotyledons, bearing a few rudimentary 
leaves and itself ending in a punctum vegetationis (Fio-. 369, ss), the 
whole constituting the plumule. The downward prolongation of the 
stem (commonly but erroneously called the radicle, for it is not a little 



DIGOTYLEDONES. 



475 



root) ends in a very sliort root, wliicb is continuous with tlie stem.* 
Under tlie proper conditions of heat and moisture, the root elongates 
and pushes out through the micro- 
pyle of the seed-coat ; at the same 
time, the stalks of the cotyledons 
elongate and thus bring the plumule 
outside of the seed-coat, the cotyle- 
dons alone remaining. During the 
first few days of its growth the 
young plant is nourished by the 
starch in the cotyledons, which in 
this species remain during the whole 
process of germination beneath the 
ground enclosed in the seed-coat. In 
the common Field Bean (Phaseolus) 
the germination is the same, except- 
ing that the hypocotyledonary stem 
elongates, and brings the cotyledons 
which have slipped out of the seed- 
coat above the ground. 

The seed of Mcinus (the Castor 
Oil Plant) contains a large embryo 
surrounded by a thin layer of endo- 
sperm (Fig. 368, /). In its germina- 
tion the root and hypocotyledonary 
stem elongate, and thus bring the 
seed-coat with the contained coty- 
ledons above the ground (Fig. 368, 
//.). The cotyledons remain within 
the seed-coat until they have absorb- 
ed all of the endosperm ; when this 
is accomplished the empty seed-coat 
falls away, and the freed cotyledons 
expand and assume to some extent 
the function of ordinary foliage 
leaves. 

The venation of the leaves of Di- 
cotyledons is easily studied by mac- 
erating them so as to remove the 
parenchyma (mesophyll), leaving 
only the fibro-vascular bundles. 
While there is as a rule a general 
likeness between them, there is yet 
an almost infinite diversity in the 




Fig. 369.— Longitudinal section of the 
axis of the embryo in the ripe seed of 
Phaseolus muUifiorus, parallel to the 
cotyledons, ss, apex of the stem ; ws, 
of the root ; ct, swelling near insertion 
of cotyledons ; «, the first internode ; 
ph, the petioles of the first foliage 
leaves ; v, -y, /, procambium of the 
fibro-vascular bundles ; he, hypocoty- 
ledonary portion of the stem (the brace 
IS too long in the figure). X 30.— After 
Sachs. 



* la some old books, and even a few recent ones, a structure called 
the collar or collum is spoken of. Dr. Gray very properly d(>fines it as 



476 



BOTANY. 



details. The general disposition of tlie smaller veins is well illustrated 
by Fig. 369a.* 

568. — The sub-class Dicot;yledones is composed of thirty- 
six cohorts, containing in all from 150 to 200 natural orders. 
For convenience, the cohorts are separated into three artifi- 
cial groups — the Apetalse, Gamopetalae, and Choripetalae 
(Polypetalse) — an arrangement which does violence to nature, 
separating widely many orders which are evidently closely 
related to each other, 

I. APETAL^. Plants whose flowers' generally have but 

a single floral envelope (calyx), 
this even, in some cases, wanting. 

569. Cohort 1. — Santalales. 

Herbs, shrubs, or trees, mostly 
parasitic, with inferior ovary, 
generally naked ovules — i.e., no 
integuments — and seeds usually 
containing endosperm. 

Order Balanophoreae. — Fleshy 
leafless parasites, mostly of the trop- 
ics. One species, Cynotnorium coccin- 
eum, of the Mediterranean region, is 
sometimes eaten. 

Order Santalaceae. — Leafy herbs. 

Fig. 369a.— Fragment of a leaf of a shrubs, or trees, mostly parasitic, num- 
showing reticulated venation. r\ bering about 200 species, which are 
margin of leaf, x 40.-After De distributed in temperate and tropical 

regions. 

Gomandra umhella'a, a perennial herb, is our most common repre- 
sentative of the order. 

Saiiinlum album, the Sandalwood Tree of South Asia, attains a height 
of seven to eight metres (25 feet). Its dark red wood is used in cabinet- 
making, and for burning incense in Buddhist temples. Other species 
from the Pacific islands also furnish sandalwood. 

The Quandang Nut of Australia is the edible fruit of a small tree, 
Fusanus acuminatus. 

"the name of an imaginary something intermediate between primary 
stem and root." 

* The student who wishes to study this subject fully should consult 
the papers of Dr. Ettingshausen, published in Denkschriften and 
Sitzungsherichte Wien. Kais. Ahid. Wissen. They are excellently il- 
lustrated with many " nature printed " plates. 




qUERNALES. 477 

Order Lorantliaceae. Tlie Mistletoe Family. Evergreen sbrubs, 
parasitic upon otlier Dicotyledons. About 450 species are known ; 
these are mostly tropical. 

Viscum album, the Mistletoe of England, Europe, and Northern 
Asia, grows abundantly upon the apple and many other trees, rarely, 
however, upon the oak. The viscid fruits aie used in making bird- 
lime, and its twigs and branches are much used in Christmas decora- 
tions in England. It was held sacred by the Druids, who made use of 
it in their religious ceremonies. 

Phoradendron flavescens, the American Mistletoe of the Southern 
Unied States, is well known. On the Pacific coast, a variety of this 
species is common on the oaks. 

Six species of Arceuthobium, small brown branching parasites on 
Conifers, are known in the United States. A. pusillum occurs in the 
Northern States. 

570. Cohort II.— Quernales. Trees and shrubs, not at 
all parasitic, with diclinous flowers, mostly in catkins, infe- 
rior ovaries, and seeds destitute of endosperm. 

Order Cupulifereae. The Oak Family. Trees or shrubs with 
simple leaves ; fruits (nuts), one-celled, one-seeded, one to three en- 
closed in an involucre. This valuable order contains about 300 species, 
which are distributed mainly in the Northern Hemisphere ; in the South- 
ern Hemisphere they occur in Chili, New Zealand, and the mountains 
of South Australia. Most of the species are astringent, which is due 
to the tannin they contain. 

The order is of great economic importance on account of its valuable 
wood, which is used not only as a fuel, but still more in the manufac- 
ture of implements and utensils, and in tlie construction of houses, 
ships, etc. It is divided into two sub-orders, which are sometimes re- 
garded as orders. 

Sub- Order Corylece, Shrubs and small trees. 

Carpinus Americana, the Blue Beech, or Hornbeam, is a small native 
tree with white, fine-grained, hard wood. As the European C. betulus 
is used in turnery, doubtless our species might be also. 

Corylus Avellana, the Filbert, is a shrub growing wild in Europe and 
Western and Northern Asia, and now cultivated in Europe and the 
United States. It is grown principally for its edible nuts, although the 
straight rod-like branches are larjjfely used in making hoops, crates for 
merchandise, etc. White Filberts, Red Filberts, Cob-nuts, aud Bar- 
celona-nuts are some of the cultivated varieties, G. Americana, the 
common wild Hazel-nut of the Eastern United States, is much like the 
preceding, but smaller in size of shrub and nuts. Its nuts are gath- 
ered and eaten, and are occasionally found in the markets, 

Ostrya Virginica, the Ironwood of the Eastern United States, is a 
email tree having a hard, fine-grained wood, which is valuable for fueL 



478 



BOl'AJVr. 



Although capable of many uses in the arts, it has been, to a great ex. 
tent, nejrlected. The trunks of the young trees are much used for 
vevers in saw-mills and log-yards, hence one of its popular names, 
Lever-wood. 

Sub-Order Qiiercinew, Mostly large trees. 

Castanea vesca, the so-called Spanish Chestnut, is a native of Asia 



0-74.— Illustrations of Quercus Robur. 




Fig. 374. 



Fig 370.— Male and female branches, with a ripe fruit at the side. 

Fig. 371.— Male flower. Magnified. 

Fig. 372.— Female flower. Magnified. 

Fig. 373. — Female flower, in vertical section. Magnified. 

Fig. 374.— Vertical section of fruit. 

Minor and the region eastward to the Himalayas. It is found in Cen. 
tral and Southeastern Europe, but it was probably introduced from the 
East 2000 or more years ago. It furnishes a valuable coarse-grained 
timber, and its fruits are the " Spanish Chestnuts " of the markets. 



qUERNALES. 479 

Several varieties occur in Nortli Africa, Japan, and North America. G. 
vesca, var. Americana, our native Chestnut, of the Eastern United 
States, is a large tree, with smaller and sweeter nuts than the Old 
World variety. Its wood, which is light, coarse-grained aud easily 
worked, is highly prized for making doors, cases, certain kiuds of fur- 
niture, etc. 

Fagus syhatica, the Beech of Europe and Western Asia, supplies a 
hard wood much used in chair-making, turnery, and in the manufac- 
ture of wooden shoes. Purple Beech, often cultivated as a curiosity, 
is a variety of this species. 

F. ferruginea, the common Beech of the Eastern United States, is a 
large spreading tree ; its wood is reddish in color, and of great hard- 
ness when dry, and is used in making carpenters' tools, and for other 
purposes. Its nuts, known as Beech-nuts or Beech-Mast, are nutritious, 
and, where abundant, are used for fattening swine. 

In Southern South America, New Zealand and Australia, there are 
six or seven evergreen species of this genus. 

The genus Quercus includes the Oaks, in all about 250 species, which 
are widely distributed in the Northern Hemisphere ; none occur be- 
yond the equator. De Candolle {Frodromus, Vol. XVI.) divides the 
genus into six sections, four of which are exclusively Southeastern' 
Asiatic. 

Section I. — The Scaly-Cupped Oaks. These include the common 
oaks of Europe and America. They are again subdivided into two sub- 
sections — viz., the White Oaks and the Black Oaks. 

(a) White Oaks. 

Quercus Bohur, the British Oak, of England and the Continent of 
Europe. It is a stately tree, supplying a most valuable timber for all 
kinds of constructive purposes, in naval, civil, and military engineering. 
It is considered to be superior to all other kinds of oak for its timber. 
The bark contains tannin, and is much used in tanning. (Figs. 370-4.) 

Q. Lusitanica, var. infectoria, of the Levant, produces the Nutgalls 
of commerce ; these are morbid growths on the petioles or midribs of 
the leaves, resulting from punctures made by an Hymenopterous insect 
of the genus Gt/nips. Their value lies in the tannin they contain. 

Q. alba, the White Oak of the Eastern United States, stands next to 
Q. Robur in the value of its timber, which is used in this country as 
British Oak is in Europe. 

Q. vireufi, the Live Oak of the Southeastern United States, and ex- 
tending westward to Texas, is a large tree, twelve to twenty metres 
(40-60 feet) high, with spreading branches, bearing small entire ever- 
green leaves. Its hard and heavy wood is very strong and durable, 
and has been much used in ship-building. 

Q. chrysolepis, the Canon Live Oak of the canons and mountain-sides 
of California, resembles the preceding in many respects, being like it 
an evergreen, and sometimes attaining a height of from twelve to sis- 



480 BOTANY. 

te('n metres or more (40-50 feet). " It furnisLes llie hardest oakwood 
of the Pacific Coast, and is used in raakin(r ox-bows, ax-bandles, etc." 
(Vasey). 

Q. Suber, the Cork Oak, is found in Southern France, Spain, Italy, 
Sardinia, and, to a limited extent, in Northern Africa. It is a spread- 
ing topped tree, bearing oval, dentate evergreen leaves. Certain lay- 
ers of cells in its bark retain their power of growth for a long time, 
and give rise to a thick mass of cork. This is removed every eight or 
ten years l)y making vertical and transverse cuts in the bark, and then 
peeling off all but the inner bark layers. Most of the supply of cork 
comes from Spain and Southern France. The tree might very profit- 
ably be grown in our Southern States and in California. 

Q. cerris, the Turkey Oak of Southeastern Europe, is a fine tree with 
deciduous, lobed leaves, and bears a considerable resemblance to our 
native Q. macrocarpa, from which it differs, however, in requiring two 
years to mature its fruits. Its timber is much used for ship-building 
and other purposes. 
(b) Black Oaks. 

In this :ire the Black Jack {Q. nigra), the Red Oak {Q. rubra), Scarlet 
Oak {Q. coccinea), Quercitron Oak, {Q. accinea, \a.T. tinctoria), all of 
the Eastern United States. The timber obtained from these is coarse- 
grained, and not so durable as that of the white oaks ; the two last fur- 
nish a yellow dye, Quercitron, which is derived from the bark. Q. agri- 
folia, the Field Oak of California is a broad-topped evergreen species. 
Its wood is of but little value. 

Section II., the Spiny-Cupped Oak, includes but a single species, 
found in California. 

Q. densiflora, the California Tan-bark Oak. This is a beautiful tree, 
often thirty metres or more in height (100 feet), with curious chestnut- 
like fruits. 

The remaining sections contain eighty to ninety species, confined en- 
tirely to India, China, Japan, and the Malay Islands. They differ in 
many respects from our oaks. 

Order Juglandaceae. — The Walnut Family. Trees and shrubs 
with pinnately compound leaves ; fruit a dry drupe, containing a hard, 
one-seeded nut (Figs. 380-382). This family includes about thirty spe- 
cies, about equally divided between North America and Asia. They 
possess an acrid aromatic principle, which has been used in medicine. 

Juglans regia, the Walnut of the Old World, is a native of Asia 
Minor and the country eastward, but long cultivated in all parts of 
Europe, and, to some extent, in this countrv. The light brown wood is 
highly prized in England for cabinet-making, the manufacture of fur- 
niture, piano-cases, gun-stocks, etc. Its thin-shelled nuts are highly 
esteemed, and are Imported from Europe in large quantities under the 
name of " English Walnuts." (Figs. 375-82.) 

J. nigra, the Black Walnut of the Eastern United States, is a giant 



qUEBNALES. 



481 



tree, often forty to fifty metres (130-160 feet) iuheiorlit. Its dark brown 
timber is fully as valuable as the preceding, and is used for the same 
purposes. It is exported in considerable quantities to England. Its 

Figs. 375-82.— Illustrations of Juglans begia. 




Fig. 380. 

Fig. 375.— Female flower cluster. Fig. 376. Female flower. 

Fig. 377.— Female flower cut vertically. Magnified. 

Fig. 378.— Male flower. Magnified. Fig. 379.— Male flower cluster. 

Fig. 380.— Ripe fruit. Fig. 381.— Endocarp, J?ig. 382.— Seed. 



482 BOTANY. 

tliick-shcMed and stronger-tasting nuts are occasionally found in the 
niarkets. 

J. cinerea, the White Walnut or Butternut, of the Eastern United 
States, is a smaller tree, furnishing a valuable lighter colored timi:)er 
than the preceding. 

Two small species occur in California, Arizona, and Texas. 

Carya aba, the Sliell-bark Hickory, and C. sulcata, both larg'e trees, 
of the Eastern United States, furnish a white, tough, and hard timber, 
useful in the manufacture of agricultural implements, and for many 
other purposes wliere great strength is required. It is not well adapted 
to use in large masses, as it is liable to early destruction through decay 
and the ravages of wood-boring insects. The fruits, known as 
" Hickory-nuts," and highly prized for eating, are found in our mar- 
kets, and are also exported to England. 

0. olwceformis, a small tree of the Southern States, furnishes a thin- 
shelled edible fruit known as the "Pecan-nut." 

Other species of Carya furnish valuable timber, and from the nuts 
of this and the preceding species valuable "nut-oils" used in paint- 
ing are obtained. 

571. — Cohort III. Asarales. Herbs, witli mostly mon- 
oclinoiis flowers, inferior ovary^ and seeds with integuments, 
containing minute embryo usually surrounded with endos- 
perm. 

Order Rafilesiaceae. — Parasites upon the stems and roots of Dicoty- 
ledons. Twenty or more species are known, distributed throughout 
the hotter parts of the vrorld. 

Rafflesia Arnoldi, of Sumatra, is the most remarkable member of the 
order. It consists of a gigantic parasitic flower nearly a metre in di- 
ameter (3 ft.), w^ith five mottled-red spreading petals. It is parasitic 
upon a woody climbing plant (Cissus angustifolia) nearly related to the 
Vine, and in its growth, forms scarcely any stem, developing almost at 
once into a giant flower-bud. It was discovered in 1818 by Dr. Arnold. 

Order Aristolochiacese. — Mostly tropical herbs, including- about 
200 species. Three species of Asarum, and three of Aristolochia occur 
in the United States. 

572.— Cohort IV. Nepenthales. Climbing shrubs, with 
diclinous flowers, a superior three to four-celled ovary, whose 
many seeds contain an endosperm. 

Order Nepenthaceae. — Plants of the East Indies and Australia, of 
ten or twelve species, all belonjjing to the genus Nepenthes. The 
leaves are prolonged into a slender tendril-like organ, upon whose ex- 
tremity there develops a hollow closed body, which finally becomes 
open by the separation of its apex in such a manner as to form a 
hinged lid (Fig. 383, d, e, f). In the cavities of these pitchers, as they 



P1PERALE8. 



483 



are called, a watery, slightly acid fluid is secreted ; upon their borders 
are secreted honey or nectar drops, which attract insects, and these fall- 
ing into the fluid within are soon dissolved by it, and tlien absorbed by 
the plant for its nour- 
ishment. 

573.— Cohort V. 
Piperales. Mostly 
herbs, with spiked 
flowers and superior 
one-celled and one- 
seeded ovary. 

Order Ceratophyl- 
lese. — Aquatic herbs of 
the Northern Hemi- 
sphere. 

Order Cliloraiitha- 
cese. — Shrubby plants, 
mostly of the tropics. 

Order Piperaceae. — 
The Pepper Family. 
Herbs, shrubs, or small 
trees, almost confined to 
the tropics ; generally 
with a pungent and 
aromatic principle. 
Over 1000 species are 
known. 

We have one species 
of Saururus in the East- 
ern, and one of A7iemi- 
opsis in the Southwest- 
ern United States. 

Two tropical genera, 
Piper and Peperomia, 
include nearly all the 
species, the first con- 
taining 630 and the sec- 
ond 382. 

Piper nigrum is a 
climbing East Indian 
plant, with heart-shaped leaves ; it bears spikes of berries, which, 
when gathered green and dried, constitute the Black Pepper of com- 
merce. The ripe berries, when dried, constitute White Pepper. Pep- 
per is now grown in the West Indies. 




"Fig. 383.— Two leaves of Nepenthe imvipullaria. o, 
short petiole ; 6, blade or expanded part of leaf ; c, ten- 
dril-like prolongation of midiib ; d, e, pitcher;/, its 
lid. In the other leaf, which is younger, the lid has not 
yet separated from the apex of "the pitcher.— After Du- 
chartre. 



484 BOTANY. 

P. Cuheha, whose dried unripe berries are known in pharmacy as 
Cubebs, is a native of the East Indies. 

P. JSetle, of the East Indies, is the Betel Pepper, whose bitter aro- 
matic leaves are mixed witli Areca-nut and lime to form a masticatory. 
(See Betel Palm, p. 46G.) 

From the thick rhizome of P. methysticum the inhabitants of many 
of the Pacific islands make a disgusting drink which is very intoxica- 
ting. 

574.— Coliort VI. Euphorbiales. Plants Avith mostly 
diclinous flowers, with a superior two to many-celled ovary ; 
seeds containing endosperm. 
Order Lacistemacese. Shrubs of tropical America. 

Order Geissolcmeee, containing a single shrub, of Southwestern 
Africa. 
Order Penasaceae. Evergreen shrubs of South Africa. 

Order Euphorbiacese. — The Spurge Family. This vast group of 
upwards of 3000 species can not be defined by anyone character. They 
may generally be distinguished by their three-celled ovaries and milky 
juice, although neither of these characters is universal throughout the 
order. The species range in size from small herbs to gigantic trees, 
and are distributed throughout all climates except beyond the Arctic 
Circle. They are much more abundant, however, in tropical countries 
than elsewhere. With few exceptions they possess an acrid principle, 
which is often poisonous. 

Many of the species are of economic importance, a few of which only 
can be mentioned here. 

Maniliot palmala and M. utilissima, slender plants of tropical Amer- 
ica, and now cultivated in many tropical countries, have .thick starchy 
roots. The starch, separated and washed, is imported under the name 
of Brazilian Arrowroot. Tapioca is prepared by heating the separated 
and washed starch upon hot plates. Cassava is made from the crushed 
roots by drying tlie pulp without separating the starch. These three 
substances are highly nutritious, and are much used as food by the 
natives, and are, moreover, largely imported into this country. Their 
value is all the more remarkable from the fact that the root of the 
second named species above is in its raw state deadly poisonous. 

Bicinvs communis, the Castor Oil plant, a native of India, is now 
widely grown for its oily seeds, from which Castor Oil is obtained by 
pressure. It is extensively grown in the Mississippi Valley. In Ger- 
many it is grown for its leaves, which are fed to silkworms. It is a 
beautiful ornamental plant, and when grown for this purpose is called 
the Palma Christa. 

Croton Oil from Oroton Tiglium, and Pinhoen Oil from Jatropha Cur- 
cas, are drastic medicines. Gum Euphorbium, the dried milky juice 



EUPH0RBIALE8. 485 

of various African and Indian species of Euphorbia, Cascarilla Bark and 
Melambo Bark from species of Croton in tropical America, are more or 
less known in pharmacy. 

Hevea Guianensis and other species of the genus, natives of the 
northern part of South America, furnish the important substance 
Caoutchouc, or India Rubber. The trees are from fifteen to thirty- 
metres in heijrht (50 to 100 ft.), and bear trifoliate leaves resembling 
those of the Scarlet-runner bean in size and shape. The natives make 
incisions into the trees, from which the milky juice exudes, and this 
evaporated constitutes the crude Caoutchouc. By heating the crude 
product with sulphur it is hardened, and is then known as " Vulcan- 
ized rubber." 

Exccecaria sebifera, the Tallow tree of China, now cultivated in the 
warmer parts of America, has its seeds coated with a white greasy sub- 
stance, which yields a valuable tallow from which candles are made. 

Aleurites Molaccana, the Candle Nut tree of India and the Pacific 
islands, produces a large oily fruit, which is itself burned and used as 
a candle, or from which a valuable oil is extracted. 

The most valuable timber of the order is furnished by Buxus semper- 
mrens, the Box tree of Europe and Asia. It is a small evergreen 
tree, with a very hard yellowish wood, invaluable in wood engraving, 
the manufacture of mathematical instruments, etc. Our chief supply 
comes from the Mediterranean ports. A dwarf variety of this species 
is used for bofdering garden walks. 

African Teak, a very heavy and hard wood from Africa, is supposed 
to be derived from Oldjieldia Africana, which has been doubtfully re- 
ferred to this order. 

Among the plants grown for ornament are many species of Euplior- 
bia, an immense genus of 700 species, distributed very widely ; in 
Africa they assume a Cactus-like aspect, having thick succulent stems. 
These and many other species are to be found in conservatories. The 
curious XylopJiylla, with flat leaf-like branches, bearing flowers upon 
their edges, is also common. 

The Sand Box tree of tropical America bears a curious many-celled 
fruit which when dry explodes with a loud report. 

The juice of many of the species is poisonous when dropped upon the 
skin, or into a wound. The Manchineel tree {Hippomane Mancinella) 
of South Florida and the West Indies is extremely poisonous, but many 
of the stories told of it are fabulous. 

Zebra Poison is the name applied to Euphorbia arborea ; branches of 
it placed in water render it sufliciently poisonous to kill the animals 
which drink it. 

575.— Cohort VII. Amentales. Woody plants, with di- 
clinous flowers, mostly in catkins ; the one or two-celled 
ovary superior, and the seeds with no endosperm. 



4SG 



BOTANY. 



Order Salicacese. — The Willow Family. Dioecious trees and shrubs 
with naked flowers — i.e., the perianth wanting. The species, of which 
there are 180, are principally found in the North Temperate and 
Arctic Zones ; beyond the tropics they are rare, and none occur in 

Figs. 384-9.— Illustrations of Salix capr^ea. 




Fig 



Fig. 384.— Male catkin and separate flower. 

Fig. 385.— Female catkin. Fig. 386.— Female flower. Magnified. 

Fig. 387.— Cross-section of ovary. Magnified. 

Fig. 388.— Kipe fruit and seed. Magnified. Fig. 389.— Embryo. Magnified. 



Australia and the South Pacific Islands. They contain a bitter astrin- 
gent principle useful in medicine as a febrifuge. 

Two genera only are known. 

Salix verminalis, S. purpurea, S. caprcBa, and other species of the 
Old World, are cultivated for basket-making. 



AMENTALES. 487 

S. Bithylonica, tlie weeping willow of Persia, is well knowu under 
cultivation. 

8. aiha and other large species of Europe furnish a light firm wood, 
much used for many purposes. 

By charring the wood a fine charcoal is obtained, much used in the 
manufacture of gunpowder. In the prairies of the Mississippi Valley 
the species last named is planted in compact rows to serve for hedges 
and to break the force of the violent winds. 

Some of the larger of our many native species might profitably be 
used for their light timber, which in some cases is quite durable. 

Populus Canadensis, the Cottonwood of North America, is a very 
large tree, whose white wood is suited to many manufacturing pur- 
poses. 

The "Lombardy Poplar," a variety of P. nigra, and a native prob- 
ably of Western and Northern Asia, and the Abele tree (P. alba) of 
Europe, are commonly grown on large grounds. 

Order Casuarineee. — Leafless trees, with pendulous Equisetum-like 
jointed stems. Twenty five species, mostly natives of Australia, are 
known. Some of them are large enough to supply a valuable timber 
for ship-building, and many are favorites for ornamental purposes in 
Australia. 

Order Myricaceae. — Monoecious or dioecious shrubs, often with a 
glandular waxy pubescence. The thirty to thirty-five species are 
widely distributed throughout the North Temperate Zone, and in trop- 
ical Asia and South Africa. 

The berries of Myrica cerifera, the Bayberry, of the Eastern United 
States, and other species in Europe are covered with a wax, which is 
gathered and made into candles. 

Order Platanaceae. — The Plane Tree Family. A small group of 
five monoecious trees, with the flowers in globose catkins. 

Platanus occidentalis, the Plane tree, Buttonwood, or Sycamore of 
the Eastern United States, is a large tree with thin white bark. Its 
reddish wood is valuable, and should be more used. A nearly related 
species occurs in California and two in Mexico. The fifth, P. oriental- 
is, is the only Old World species. 

Order Betulaceae. — The Birch Family. Monoecious trees with 
flowers in slender catkins. The species, forty or more in number, are 
found throughout the North Temperate Zone, and in South America. 

Betula alba, of Northern Europe, Northern Asia, and North America, 
is a useful species. Its wood is valuable for fuel, use in manufactures, 
and for making into charcoal. Its bark is made into shoes, boxes, etc. ; 
it is used in tanning leather, and from it by distillation an oil is ob- 
tained which gives to Russia leather its peculiar scent. The people in 
the high north latitudes also use the cellular and starchy part of the 
bark for food. 



488 noTAyr. 

The bark of 7>. pnpyracea, of the Eastern Uuited States, is used hr 
the Indians for niakiu(r their " birch bark canoes." 

The wood of species of Alnus, the Alders, is very durable whea 
placed under the ground or water. It is also made into wooden bowls 
and other domestic utensils, and is in some j^laces grown for making 
into charcoal. 

576.— Cohort VIII. Urticales. Mostly diclinous plants, 
with superior one-celled oyary, and single seed mostly with 
an endosj^erm. 

Order TJlraacese. — The Elm Family. Trees or shrubs of the Nonh 
Temperate Zone, having mostly monoclinous flowers, and a \vatery 
juice. About one hundred and thirty species are known, 

Ulmns campestris, the common Elm of Euroiie and Western Siberia, 
is a large tree, thirty to forty metres (100 to 130 ft.) high. Its timber is 
valuable for works under ground or in water, and is besides much used 
by wheelwrights. The tree is common in American gardens, 

U. Americana, the American White Elm of the Eastern United 
States, and now much grown in Europe, is one of our finest looking 
trees, and deservedly popular as an ornament in large grounds. Its 
timber is valuable when used entirely under water or in the ground, 
or when kept continuously dry ; otherwise it decays rapidly. 

U. fulva, the Slippery Elm of the Eastern United States, supplies a . 
valuable timber, and its mucilaginous inner bark is used for medical 
and surgical purposes. 

Celtis occidentalis, the Hackberry of the Eastern United States, is a 
lofty tree which furnishes a white hard timber, which is not, however, 
very durable. 

Order Cannabineae. — This contains the two dioecious herbs, the 
Hemp and the Hop. 

Cannabis sativa, the Hemp, is a tall herb, two to three metres (7 to 
10 ft.) in height, indigenous in the northern parts of India, but now 
generally cultivated in all temperate and warm regions. Under the 
names of giinja, bhang, churrus, JiascMscli, etc., the natives of India and 
Central Africa use the dried leaves, stems, flowers, and the resinous 
matter which develops on the plant. When smoked, or drank as an 
infusion, these are highly Intoxicating. The fibre obtained from its 
bark is strong, and much used for cordage. 

Ilumulus Lupulus: the Hop, a native of temperate Europe, Asia, and 
North America, is grown for its bitter principle, Lupulin, which de- 
velops in the female flower clusters, and which is much used in the 
manufacture of beer, ale, etc. 

Order Moracese. — The Mulberry Family. Trees or shrubs, con- 
taining a milky juice. The order contains between 800 and 1000 spe- 
cies, and they are for the greater part natives of the tropics. Many 



UBTIOALES. 



489 



of them contain an acrid poisonous principle, wLile some are not only 
innoxious, but afford wholesome food. 

Artocarpus ivcim, the Bread Fruit tree, a native of the Pacific Is- 
lands, and now common in tropical countries, attains a height of f loni 
six to nine metres (20 to 30 ft.). The fleshy receptacle and agglomerated 
carpels form a mass as large as a man's head. This " fruit," when 
gathered a little before it is ripe, and baked, looks and tastes much 
like bread, and is largely eaten by tropical people. The Jack Fruit of 
India {A. integrifoUus) is similar, but not so palatable. 

Ficus Carica, the Fig, a native of Western or Southern Asia, has 

Figs. 390, 91.— Illustrations of Horaces. 





Fig. 390. 



Fig. 391. 



Fig. 390.— Fl'isliy concave receptacle of Dorstenia, bearing male and female flowers. 
Fig. 391. -Fleshy closed receptacle oi Ficus ^ cut vertically, containing male flowers 
above and female below. 



been cultivated for ages. It is now found in all tropical and sub-trop- 
ical countries. It is grown in the Southern United States and in Cali- 
fornia. The tree attains a height of from five to six metres (16 to 20 
ft.), and bears pear-shaped closed receptacles (Fig, 391), inside of which 
are the minute flowers. The ripened and dried receptacles constitute 
the Figs of commerce. Our supply comes mainly from the Mediter- 
ranean Basin. 

Galactodendron utile {Brosimum utile), a tall tree, twenty-five metres 
high (80 ft.), of Venezuela, whose milky juice is used by the natives as 
a substitute for milk, to which it bears a close resemblance. The tree 
>s hence called the Cow Tree. 



4\}0 BOTANY. 

Mows nigra, the Mulberry tree of Persia, is now cultivated in Eu- 
rope and the United Stales for its edible fruit masses. Its leaves are 
used to feed to silkworms, but not to so g'reat an extent as those of 
M. alba, the White Mulberry, which has been used from time iujme- 
inorial for this purpose in China. 

M. rubra, a native of the Eastern United States, bears valual^le 
fruits. 

Several of the trees of the order ^Meld Caoutchouc. The most im- 
portant of these are Mcus elastica of India, and Cafsiilloa elastica of 
Mexico and the West Indies ; the first named is a common greenhouse 
plant. 

Gum Tjac is a resinous exudation collected from an Indian species of 
Ficus, whose branches have been punctured by an hemipterous insect. 
Coccus lacca. 

The wood of many species is valuable. 

Brosimum Ouia?iensis, of Guiana, produces the beautifully mottled 
and streaked Snakewood, much prized by cabinetmakers, and for 
making bows. 

Madura aurantiaca, a tree eight to fifteen metres (25 to 50 ft.) high, 
growing in Arkansas, Texas, etc., supplies a very hard wood used by 
the Indians for making bows, hence one of its names, " Bow-wood." 
Under the name of Osage Orange, it is much used as a hedge plant. 
Its wood yields a coloring matter used as a dye, and from 31. tinctoria, 
of the West Indies, the dye known as Fustic is obtained. 

The bark of many species yields tenacious fibres ; thus from the 
Paper Mnlherry {Broussonetia papyri/era), a Chinese and Japanese tree 
eight to fifteen metres (25 to 50 ft.) in height, the Chinese make paper, 
and the Pacific Islanders make cloth. One of the most remarkable is 
the Sack tree (Antiaris saccidora) of Western India ; its bark is so 
tenacious that after beating, it may be removed in sections, which are 
used for sacks for carrying rice, etc. 

The Upas Tree of Java {Antiaris toxicaria) is poisonous, but it is by 
no means as virulent as it has been described. It frequently grows in 
volcanic valleys partially filled with carbon dioxide and oiher noxious 
gases, and to this fact is doubtless due the marvellous stories told of it. 
However, from its juice the natives prepare a deadly poison for ilieir 
arrows. 

The Banyan Tree {Ficus Indica) is remarkable for its numerous ad- 
ventitious roots, which grow down from its horizontal branches, and 
thus enable it to extend its top very greatly. One on the Nerbudda, 
with three hundred and twenty of such supporting roots, covers an 
area two hundred metres (650 ft.) in diameter. 

Order Urticacess. — The Nettle Family. Herbs, shrubs, or trees, 
with a limpid juice; they occur in all climates, but mostly in the 
tropics. More than five hundred species are known. Many of the 
species possess a valuable fibrous bark. (Figs. 392-7.) 



DAPHNALE8. 



491 




Fig. 392. 



Bmhmeria 7uvea, the China Grass or Ramie, a perennial lierbaceoua 
plant, may fairly rival Flax in the fine and durable fibres it produces. 
It has been introduced into the Southern United States and California. 
There is still some difficulty in separating the fibres from the woody 
portions of the plant, and this has prevented its more extensive use. 

The Stinging Nettles include ten genera, of which the most impor- 
tant are Urtica, which includes our common species, and Laportea, 
represented by our Wood Nettle ; to tbe latter belongs the Tree Nettle, 
L. gigas, of Australia, which reaches a height of Irom fifteen to forty 
metres (50 to 130 ft.), and whose sting is so severe as to produce dan- 
gerous results. „ , 

Figs. 392-7.— Illustkations of Urtica urens. 

677. — Cohort 
IX. Daphnales. 

Mostly shrubs or 
trees, with mono- 
clinous flowers ; 
ovary superior, 
one-celled, with a 
single seed con- 
taining no endo- 
sperm. 

Order Protea- 
cese. — A family of 
about 1000 species, 
confined almost en- 
tirely to the South- 
ern Hemisphere, and 
occurring in greatest 
abundance in Aus- 
tralia and South 
Africa. Many spe- 
cies, especially of the 

genus Banksia, are cultivated in conservatories, 
ble timber. 

Grevillea robusta, the Silk Oak of Australia, attains a height of 
twenty-four to thirty metres (80 to 100 ft.), with a diameter of two 
metres or more, and supplies valuable timber. 

Knightia excelsa is a valuable New Zt-aland timber tree thirty metres 
(100 ft.) or more in heigbt. 

Leucadendron argenteum, tbe Silver Tree of the Cape of Good Hope, 
has silvery lanceolate leaves ; its wood is much used tor fuel. 

Protea grandiflora, the " Wagen-bo(mi " of the same region, is used 
by wheelwrights in the manufacture of wagon wheels. 

Order Elseagnaceee. — A small order, of sixteen species, of trees or 




Fig. 394. 



Fig. 396. 



Fig. 397. 



Fig. 392.— Male flower. Magnified 
Fig. 393.— Diagram of male flower. 
Fig. 394. -Female flower. Magnified. 
Fig. 395.— Diagram of female flower. 
Fig 396.— Seed. Magnified. 
Fig- 397.— Section of seed. Magnified. 



A few furnish valua- 



492 



BOTANY. 



elirubs, found mostly ir. the mountains of Southern Asia. Tlie Oleaster 
{Elcmgnns hortensis) of Southern Europe is there much planted for its 
odoriferous flowers ; it i.^ occasionally planted in this countiy. 

Shtphe dia Canadensis, of the Northeastern United States, and S. 
aryentta, the Buffalo-Berry of the Rocky Mountains and the Great 
Plains, are frequently cultivated for their acid fruits, which are about 
as lar<4e as currants. 

Order Hernandieae, including a few tropical trees. 

Figs. 398-402.— Illustrations of Laurus kobilis. 




Fig. 400. 

Pig. 398.— Male flower. Magnified. 
Fig, 400.— F( m;ile flow er. Magnified. 
Fig. 402.— Diagram of female flower. 



Fig. 401. 



Fig. 402. 



Fig. 399. — Diagram of male flower. 
Fig. 401.— Section of female flower. 



Order Thymelseaceae. — Shrubby plants, mostly of the Southern 
Hemisphere. .Of the 378 species we have in the United States but one 
representative, viz., the Moose- wood or " Wicopy" {Dii-ca palustris), a 
small shrub with exceedingly touirh bark. 

Daphne Mezereum, a poisonous shrub of Europe, is frequently culti- 
vated here for its sweet-smellinor flowers. 

The bark of many species is used in their native countries for making 



LA URALE8. 



493 



fabrics, cordage, etc. Lagetta lintearia, of Jamaica, is tlie Lace-Bark 
Tree, so called on account of its delicate inner bark, 

578.— Cohort X. Laurales. — Herbs, shrubs, and trees, 
with mostly diclinous flowers ; ovary superior, one-celled, 
the single seed sometimes with, and sometimes without 
endosperm. 

Order Lauraceae. — The Laurel Family. Aromatic trees and shrubs 
Figs. 403-5.— Illustbations of Mtristica pragrans. 




Fig. 403. 



Fig. 405. 



Fig. 403.— Fruit, showing seed and aril. Fig. 404.— Seed and aril. 

Fig. 405.— Seed cut vertically, showing embryo below. 

(rarely parasitic herbs) with free stamens, and a pendulous seed with- 
out endosperm. About 1000 species are known, occurring in the trop- 
ical and temperate climates of both hemispheres. 

LnuTUS nobilis, the Bay or Laurel of Southern Europe, is a fine 
sprnadino'-topped evergreen tree, twelve to fifteen metres (40 to 50 ft.) 
higli. In ancient times its leaves were used to crown heroes, but now 



494 BOTANY. 

tliey are mad*? use of in flavoring custards, puddings, etc., and are put 
into boxes of figs to oive them a factitious flavor. (Figs. 398-402. j 

Umhellularia Californica {Tetranthera Calif ornicn)^ tlie California 
Laurel, resembles the preceding, and like it is evergreen. Its wood is 
used in cabinet-making. 

Persea gratissima, a small West Indian tree, produces a delicious 
fruit called Avocado- or Alligator-Pear. 

Among the aromatic products are Cinnamon, the bark of Cinna- 
momum Zeylaidcum, a small tree of Ceylon ; Cassia Bark and Cassia 
buds, from C. Cansla, of Ceylon ; Camphor, a gummy matter distilled 
from the w^ood of 0. Camphora, a tree of China and Japan ; Sassafras 
Bark, from Sassafras officinale, of the Eastern United States. 

The wood of the two last-named trees is valuable in cabinet-making, 
as is also that of the Red Bay {Persea) of the Southern United States. 

Nectandra Bodiei, the Greenheart Tree of Guiana, is a large tree 
furnishing an exceedingly heavy, dark colored, and durable timber, 
highly valued in naval constructions. 

Order Myristicaceae. — The Nutmeg Family. Aromatic trees, with 
monadelphous stamens, and an erect seed containing endosperm. The 
seventy five species are all tropical, and most of them occur in the In- 
dian region. They all belong to the genus Myris'ica. 

3Jyristica fragrans, the Nutmeg Tree of the Malay Archipelago, at- 
tains a height of six to nine metres (20 to 30 ft.; ; it bears a fleshy fruit 
of the size of a walnut and inside of this is a large seed covered with a 
red, branching aril (Figs. 403-4). The seed, deprived of its integu- 
ments, is the nutmeg of commerce, while the dried aril is the Mace, 
both well known condiments. 

Some of the other species are occasionally used, but they are much 
less valuable. 

Order Monimiaceae. — Aromatic trees or shrubs of the tropics and 
south temperate zone. About 150 species are known. The Tasmaiiian 
" Sassafras Tree" {Atherosperma moschata), the Australian " Sassafras 
Tree" {Doryphora Sassafras), and the New Zealand "Sassafras" 
(Laurelia JYovw Zelandioe), are large trees thirty to forty-five metres 
(100 to 150 it.) high, whose timber is valuable for ship-building. 

579.— Cohort XI. Chenopodiales. Monoclinous (rarely 
diclinous) herbs or shrubs; o^ary superior, one-celled, the 
single seed containing endosperm. 

Order Paronychieae.— A small group of mostly herbaceous plants, 
the flowers generally with both sepals and petals ; the latter, however, 
rudimentary. The order has close affinities with Caryophyllaceae, of 
which it should probably be considered a sub-order. 

Order Basellacese.— Herbaceous, often climbing plants of the 
tropics. One species from South America (BoussiiigauUia baselloides) 



CHENOPODIALES. 



495 



is cultivated as an ornamental climber under the name of Madeira 
Vine. The starchy tubers of another species, Uducus tuberosus, are 
used in Peru as substitutes for the potato. 

Order Chenopodiaceae. — Herbs, shrubs, or rarely trees, whose 
flowers have an herbaceous perianth. About 500 species, distributed 
in all climates, are known. (Figs. 406-11.) 

Beta vulgaris, the Common Beet, is a native of Southern Europe. 
The Sugar Beet and Mangel Wurzel are only varieties of the Common 
Beet; the first is extensively cultivated in France for the sugar which 

Figs. 406-10.— Illustbations of Beta vulgaeis. 




Fig. 408. 
Fig. 406.— Flower. Magnified. 
Fig. 408.— Section of flower. Magnified. 
Fig. 410.— Seed. Magnified. 



Fig. 410. 

Fig. 407.— Diagram of flower. 
Fig. 409.— Three fruits. Magnified. 



is obtained from its sweet juice ; its cultivation in this country is yet 
in its infancy. 

Ghenopodium Quinoa, a Peruvian annual, is cultivated in Western 
South America for its nutritions seeds, which are ground into meal, and 
used as an article of food. 

C. arribrosioides, Wormseed, from tropical America, used somewhat 
in medicine, and other species of the genus, have become common weeds 
in fields and gardens. 

Syinacia olera,c.ea. Common Garden Spinach, is an Oriental plant 
much cultivated as a pot herb. 



496 



BOTANY. 



Order Amarantacese. — Herbs, rarely shrubs, wliose flowers have a 
scarious perianth. The order, which contains about 500 species, is 
mostly tropical, a few occurring in temperate climates, but none at all 
in cold ones. 

In India some of the species are cultivated, for their starchy seeds, 
which are used for food. 

Several species are cultivated with us for their ornamental foliage, 
{AcJiyranthes) or their colored inflorescence, e.g.. 
Cock's Comb (Celosia), Globe Amaranth {Gomphre- 
na), etc. 

Amarantus retroflexus and A. albns, are common 
weeds in fields ; the latter, in the prairie region, 
grows in a globular form, and in the autumn breaks 
off" at the root, and is blown for miles across the 
country. On account of this habit of growth it is called the " Tumble 
Weed.'" 

Order Polygonacese. — The Buckwheat Family. Herbs, shrubs, or 
rarely trees, mostly with sheathing stipules and knotted-jointed stems ; 
perianth often petaloid. The 600 species constituting the order are 
mostly natives of temperate regions. 

Fagopyrum esculentum, Buckwheat, a native of Central or Northern 




Fig. 411.— Section 
of seed of Chenopo- 
divm. Mamified. 



Figs. 412-15.— Illustrations of Fagopyrum esculentum. 




Fig. 412. 

Fig. 412.— Flower. Magnified. 
Fig. 414.— Pistil. Magnified. 



Fig. 413. 



Fig. 414. 



Fig. 415. 



Fig. 413.— Diagram of flower. 
Fig. 415.— Fruit Magnified, 



Asia, is now extensively grown in Europe and America for its nutri- 
tious seeds, and for its honey-producing flowers (Figs. 412-15.) 

Polygonum mnphibium, var. terrestre, a native of the United States, 
has been used in the Mississippi valley as a substitute for bark in the 
process of tanning. It contains a considerable quantity of tannin. 

Rheum officinale. Oriental Rhubarb, is a native of Southeastern 
Asia ; its roots constitute the ofiicinal Rhubarb. Other species are 
often used as substitutes. 



LAMIALES. 49? 

R. Rliaponticum, a native of Western Asia, is commonly grown in 
gardens under the name of "Pie Plant," its petioles are used for tlie 
pleasant acid tliey contain. 

Many species are weeds of fields and gardens ; sucli are Smartweed, 
and Black Bindweed {Polygonum, sp.). Docks and Sorrel {Eumex, sp.). 

Order Phytolaccacese. — Mostly tropical herbs, sometimes shrubs 
or trees, usually with several free or united carpels. About eighty 
species are known, most of which are more or less acrid. 

Phytolacca decandra, the Common Pokeweed, is our most notable 
representative. It is, however, a doubtful native. 

Order Nyctaginacese, — Mostly tropical herbs, shrubs, or trees with 
opposite leaves and tumid joints ; iiowers gamophyllous. About 
200 species are known. The roots of many of the species are purgative 
or emetic. 

Ahronia, of several species. Mirabilis, sp., the Four O'clock, or 
Marvel of Peru, and some others, are cultivated as ornaments. 

II. GAMOPETAL^.— Plants whose flowers generally 
have both sepals and petals, the latter connately united. 

580.— Cohort XII. Lamiales. Plants with zygomorphic 
flowers, superior ovaries, indehiscent fruits, with the seeds 
solitary in the two to four cells. 

Order Labiatae. — The Mint Family. Aromatic herbs or shrubs, 
with four-angled stems and opposite leaves. The species, of which 
there are abi)ut 2500, are abundant in temperate and warm climates, 
but are rare in cool regions. We have about 200 native species in 
North America. (Figs. 416-18.) 

Considering the size of the order, it ranks low from an economic 
standpoint. Tlie aromatic herbage has led to the use of many species 
as domestic remedies, few of which, however, are really valuable. 
Nevertheless, there are many species yielding minor products which 
are of some value. 

Hyssopus officinalis, Hyssop, a small shrub of Southern Europe, is 
commonly cultivated in gardens as a domestic medicine. 

Hedeoma pulegioides, American Pennyroyal, is an officinal herb. 

Lavandula vera, Lavender, is a shrubby plant of the South of 
Europe, cultivated in gardens, and used as a domestic perfume. Oil 
of Lavender is obtained from it by distillation. 

Mentha piperita, Peppermint, intntduced from Europe, yields Oil 
of Peppermint by distillation. It is extensively grown in Southern 
Michigan and New York. 

Marruhium vulgare, White Horehound, of Europe, is commonly 
found in gardens; its dried herbage is officinal. 

Rosmarinus officinalis, Rosemary, Thymus vulgaris. Thyme, and Sal- 



498 



BOTANY. 



ua officinalis. Garden Sage, are small South European shrubs, now 
to be found in all gardens. 

Catnip, Balm, Horsemint, and many others are used more or less as 
family medicines, for which purpose they are well suited, being harm- 
less and feebly operative. 

Several tropical species of Salvia are grown as ornaments, as are also 
Coleus and Perilla, from Southeastern Asia. 

Order Verbenaceae. — The Vervain Family. Herbs, shrubs, or 
trees, usually not aromatic, with mostly four-angled stems. The 
species number about 700, and are chiefly tropical. They generally 
possess a bitter and astringent principle. 

With us the order is esteemed principally for its ornamental value. 

Figs. 416-18.— IiiLUSTBAxioNs of Labiate. 






Fig. 416. 



Fig. 417. 



Fig. 418. 



Fig. 416.— Flower of Lamium, side view. 

Fig. 417.— Vertical section of flower. Magnified, 

Fig. 418.— Diiigram of flower. 

Besides the several South American species of Verbena in common cul- 
tivation, the so-called Lemon Verbena {Lippia citroidora) from Chili, 
and the species of Lantana from tropical America, there are to be 
found in conservatories many showy species of Clerodendvon, from Asia. 

Tectona grandis, the Teak Tree of India, is a gigantic tree whose 
yellowish durable wood is much used in ship-building. It is said to 
resist the attacks of Limnoria terebrans when exposed in sea- water. 

Vitex littoralis, of New Zealand, and other species, growing in the 
Indo- Australian region, are large and valuable timber trees. 

Order Myoporineee. — Mostly Australian shrubs, of no value. 

581.— Cohort XHE. Personales. Plants with zygomor- 
phic flowers, superior ovtiries. and dehiscent many-seeded 
fruits. 



PER80NALE8. 



499 



Order Acanthaceae. — Tlie Acanthus Family. Herbs, mostly of 
the tropics, numbering about 1500 species. Thirty-five or forty species 
occur in North America, mostly, however, in the South and West. 
Some of the exotic species are grown in conservatories, e.g., Jasticia 
Thunbergia, etc. 

Order Pedaliaceae. — Herbs with glandular hairs. The most im- 
portant species are the Asiatic Sesamum Lidicum and 8. orie7itale, 
whose seeds yield an oil much used as food by the inhabitants of the 
tropics. 

Martynia proboscidia, the Unicorn Plant of the Southwestern United 
States, is notable for its two-hooked fruits. 

Order Bignoniacese. — Mostly woody plants, numbering about 500 
species, and natives, for the most part, of the tropics. Many are cul- 



FiGs. 419-22.— Illustrations of Scbophulariace^ (Scrophularia, ep.). 




Fig. 419. 



Fig. 420, 



Fig. 419.— Flower. Magnified. 
Kg. 421.— Pistil. Magnified. 



Fig. 421. 



Fig. 420.— Section of flower. 
Fig. 422.— Diagram of flower. 



tivated for their fine flowers among these are the species of Bignonia ; 
Tecoma, etc. 

Gatalpa hignonioides, the Common Catalpa of the Southern United 
States, is a fine tree for shade and ornament. Its wood is said to be 
very durable. C. speciosa is much hardier than the precedin<r. 

Crescentia Cujete, the Calabash Tree of tropical America, produces a 
large pulpy fruit whose hard rind is used as a water-vessel. 

Order Gesneraceee. — Mostly tropical plants, represented by Achi- 
menes, Oloxinia, Gesnera, etc., cultivated in conservatories. 

Order Columelliaceae. — Evergreen trees or shrubs of tropical 
America. 

Order Lentibulariaceae. — The Bladderwort Family. Mostly 
aquatic or marsh plants, of temperate and warm regions, interesting on 
account of the insect-catcliing bladders of the aquatic species. (For 



500 BOTANY. 

the particu/ars as to Pinguicula, see Darwin's "Insectivorous Plants,*'' 
pp. 368-394, and for Utricularia, pp. 395-444.) 

Order Orobanchaceae. — Leafless parasitic herbs, numbering 150 
species, widely distributed. VV'e have about a dozen native species in 
the United iStates. 

Order Scrophulariaceae. — The Figwort Family. Herbs or shrubs, 
rarely trees, with two-celled ovaries and central placentae. The 
species, of which there are about 2000, are found in all parts of the 
world, extending iu both hemispheres to the limits of vegetation. 
Many of the species contain an acrid poisonous principle. (Figs. 419-22.) 

Digitalis purpurea, the Foxglove, a small plant of Europe, affords 
the drug Digitalis, which is officinal. 

Many species are cultivated for their fine flowers ; among these are 
the Snapdragon (AntirrJdnum), Monkey Flower {Mimulus), Mauran- 
dia, Pentstemon, Veronica, Calceolaria, etc. , etc. 

Paulownia imperialis, a small tree of Japan, is planted in the 
Southern States. 

Verbascum Thapsus, the Common Mullein, is a weed introduced from 
Europe. 

582.— Cohort XIV". Polemoniales. Plants with alter- 
nate leaves, regular flowers, stamens isomerous with the 
corolla lobes, and ovary superior. 

Order Solanaceee. — The Nightshade Family, Herbaceous or woody 
plants with a watery juice ; ovary two-celled, many ovuled. This 
large order of from 1200 to 1500 species, which are chiefly tropical, is 
pervaded by a more or less poisonous principle. (Figs. 423-7.) 

There are, however, a few valuable food plants. 

Solanum tuberosum, the Potato, is a native of America from Mexico 
to Chili, and a variety of it (var. boreale) even occurs in New Mexico. 
The potato was introduced into Spain in the early part of the sixteenth 
century, and into England by Sir Walter Raleigh in 1586, but for 
nearly a century from the latter date it was little used. It is now, 
however, grown extensively in nearly all countries. In its wild state 
its tubers are not more than two to three centimetres in diameter, but 
by culture and selection they have been increased fifteen to twenty 
times in bulk. 

Solanum Melongena, the Egg Plant, of South America, is now grown 
with us for its egg-shaped edible fruits. 

Lycopersicum ebculentum, the Tomato, of South America, is grown 
in most warm and temperate countries for its wholesome fruits. 

Physalis Alktkengi, the Winter Cherry or Strawberry Tomato, of 
the South of Europe, is grown in our gardens for its edible fruit, which 
is enclosed in the inflated calyx. Our native species of this genus, 
called commonly Ground Cherries, are valuable for food. 



POLEMONIALES. 



501 



Capsicum annuum, of Soutli America, and other species of the genus, 
Figs. 423-7.— Illustkations of SolA-NAOB^e. 





"Sm, 4SA:. 




Fig 425. 




Fig. 423. 

Fig. 423.— Flowering stem of Potato. 

Fig. 424.— Flower of Bittersweet. Magnified. 

Fig. 425.— Diagram of Potato flower. 

Fig. 426.— Calyx and pistil of Potato. Magnified. 

Fig. 427.— Section of seed of Bittersweet. Magnified. 

bear exceedingly pungent pods, known as Peppers. The ground 
pods constitute the Cayenne Pepper of commerce. 



502 BOTAXY. 

Atropa Belladonna, the Deadly Ninrhtsliade, Hyoscyamus niger, 
Heubane, said Datura Stramonium, the Thorn Apple, all of the Old 
World, supply powerful narcotic medicines. That from the first, un- 
der the name of Belladouna, is much used bv oculists to dilate the pu- 
pil of the eye. 

Nicotiana Tahacum, Tobacco, a South American herb, was cultivated 
by the American aborigines long be:ore the advent of Europeans. It 
was taken to Spain about the beginning of the sisteentb century, and. 
to England from sixty to eighty years later. It is now extensively 
cultivated in many countries, especially in the United States, and is 
used by all the civilized nations of the globe. Two or three other 
species are also cultivated in different parts of the world. 

Among the ornamental plants of the order are species of Cestrum and 
Datura, from South America and Mexico; Lycium, from Europe; 
Petunia, from South America, etc., etc. 

The Thorn Apple mentioned above, and the Black Nightshade {So- 
lanurn, nigrum) are common as weeds. The little black berries of the 
latter are made into pies and other pastry in the Mississippi Valley. 

Order Convolvulaceae. — Herbaceous climbers, rarely shrubs, often- 
■with a milky juice; ovary of 1-5 cells, each 2-, rarely 1-4, ovuled. 
About 800 species are known, distributed mostly in tropical and warm 
temperate regions. They generally possess an acrid principle. 

The Common Morning-Gflory {Iporncea purpurea?) and one or two near 
relatives, all from tropical America, are familiar ornamental climbers. 

Ipomcea Batatas, the Sweet Potato of India, has long been cultivated 
in many warm and temperate climates for its nutritious roots. 

The purgative drug Jalap is derived from the root of a Mexican 
plant Ipom cea p u rga . 

Convolvulus Scammonia, of Western Asia, yields the drug Scamraony, 
and from the wood of C. Scoparius, a shrubby species of the Canary 
Islands, Oil of Rhodium is extracted. 

Cuscuta, the parasitic Dodder, includes many species. 

Order Borrag-inacese. — The Borage Family. Usually hispid herbs, 
shrubs, or trees, with a four-parted ovary, each part one-ovuled. The 
1200 species are distributed throughout the world, although they are 
most numerous in Southern Europe and Western and Central Asia. 
Many of the species possess a mucilaginous property useful in making 
cooling drinks, and the roots of some contain purple or brown dyes. 

Anchum tinctoria, of the South of Europe, is grown in France and 
Germany for its roots, which yield the red dye called Alkanet. 

Among the commonly cultivated ornamental plants may be men- 
tioned the Forget-me-not (Myosotis palustris) of Furore and the Helio- 
trope {Heliotr opium Peruvianum) of Peru. There are several native 
and introduced species which are vile weeds. 

Order Hydrophyllacese. — A small order of mostly American herbs. 
closely related to ihe preceding. 



aSNTIANALES. 



503 



Species of NemopMla, Phacelia, Wldtlaxm, etc., are cultivated in 
flower gardens. 

Order Polemoniaceee. — Mostly herbs of Xorth America and Xorth- 
ern Asia, numberino; about 150 species. 

Species of Phlox, Gilia, Polemonium, ColcEa, etc., are cultivated in 
flower gardens. 

583.— Cohort XV. Gentianales. Plants with opposite 
leaves, regular flowers, superior oyary, and tlie stamens usu- 
ally as many as the corolla lobes and alternate with them. 

Order GentianaceEe. — The Gentian Family. Annual or perennial 
herbs, with a watery juice ; ovary generally one-celled, with many 
ovules. The species, of which there are about 500, are found mostly 
in temperate and cold climates. They possess a bitter principle, which 
has been employed in medicine. We have many very pretty wild 
species. 

Order Loganiaceae. — Woody plants almost entirely of the tropics, 
with two-celled ovaries. About 350 species are known ; they contain 
a bitter principle which is often exceedingly poisonous. 

Strychnos nux-vomica is a small tree of India, bearing an orange-like 
fruit containing numerous large flatfish seeds (2 cm. in diameter). 
These seeds constitute the poisonous drug, Nux Vomica ; they con- 
tain two alkaloids to which their activity is due, viz, Strychnia 
(C21 H22 N2 O2) and Brucia (C23 Has N2 O4 + 4 Ha 0). The ordinary 
form of the first as found in the shops is a Sulphate of Strychnia. 

8. toxifera, a tree of the northern parts of South America, yields 
from its bark and young wood the famous poison known as Curare, 
Urari, Ourari, Woorara, etc. 

S. Tieute, a Javanese climber, furnishes the virulent Upas Tieute 
"or Tjettek with which the natives poison their arrows. 

Order Asclepiadaceae. — The Milkweed Family. Woody or herba- 
ceous plants, with a milky juice ; ovaries two, distinct, but with a 
single common stigma ; pollen agglutinated into masses (pollinia). 
This large order of about 1300 species is chiefly tropical, being abun- 
dantly represented in America, Africa, and Asia. The milky juice con- 
tains Caoutchouc, and usually acrid and poisonous principles. But few 
of the species are of sufficient economic importance to demand notice. 
Many have a local reputation as domestic medicines. (Figs. 428-82.) 

Some are favorites in the flower garden or conservatory, 6.^., the Wax 
Plant of India {Hoya carnosa), species of Ceropegia, StepJianotis, Peri- 
ploca, etc. The South African Stapelias resemble Cacti, being fleshy 
and leafless 

The peculiar structure of the flowers in this order has recently been 
shown to be for the purpose of securing the services of insects in the 
process of pollination. 



502 BOTANY. 

Atropa Belladonna, the Deadly Ni<riitsljade, Ilyoscydmus niger. 
Henbane, a.nd Batura Stramonium, ilie Thorn Apple, all of the Old 
World, supply powerful narcotic medicines. That from the first, un- 
der the name of Belladonna, is much used by oculists to dilate the pu- 
pil of the eye. 

Nicotiana Tdbacum, Tobacco, a South American herb, was cultivated 
by the American aborigines long before the advent of Europeans. It 
was taken to Spain about the beginning of the sixteenth century, and 
to England from sixty to eighty years later. It is now extensively 
cultivated in many countries, especially in the United States, and is 
used by all the civilized nations of the globe. Two or three other 
species are also cultivated in different parts of the world. 

Among the ornamental plants of the order are species of Oestrum and 
Datura, from South America and Mexico ; Lycium, from Europe ; 
Petunia, from South America, etc., etc. 

The Thorn Apple mentioned above, and the Black Nightshade {So- 
lanum nigrum) are common as weeds. The little black berries of the 
latter are made into pies and other pastry in the Mississippi Valley. 

Order Convolvulacese. — Herbaceous climbers, rarely shrubs, often 
with a milky juice ; ovary of 1-5 cells, each 2-, rarely 1-4, ovuled. 
About 800 species are known, distributed mostly in tropical and warm 
temperate regions. They generally possess an acrid principle. 

The Common Morning-Glory {Ipomaa purpurea) and one or two near 
relatives, all from tropical America, are familiar ornamental climbers. 

Ipomaa Batatas, the Sweet Potato of India, has long been cultivated 
in many warm and temperate climates for its nutritious roots. 

The purgative drug Jalap is derived from the root of a Mexican 
plant Ipomma purga. 

Convolvulus Scammonia, of Western Asia, yields the drug Scammony, 
and from the wood of C. Scoparius, a shrubby species of the Canary 
Islands, Oil of Rhodium is extracted. 

Cuscuta, the parasitic Dodder, includes many species. 

Order BorraginaceaB. — The Borage Family. Usually hispid herbs, 
shrubs, or trees, with a four-parted ovary, each part one-ovuled. The 
1200 species are distributed throughout the world, although they are 
most numerous in Southern Europe and W^estern and Central Asia. 
Many of the species possess a mucilaginous property useful in making 
cooling drinks, and the roots of some contain purple or brown dyes. 

Anchusa tinctoria, of the South of Europe, is grown in France and 
Germany for its roots, which yield the red dye called Alkanet. 

Among the commonly cultivated ornamental plants may be men- 
tioned the Forget-me-not {Myosotis palustris) of Europe and the Helio- 
trope {HeliotTopium Peruvianum) of Peru. There are several native 
and introduced species which are vile weeds. 

Order Hydrophyllacese. — A small order of mostly American herbs., 
closely related to the preceding. 



GENTIANALE8. 503 

Species of NemopJiila, Phacelia, Whitlama, etc., are cultivated in 
flower gardens. 

Order Polemoniacese. — Mostly herbs of North America and North- 
ern Asia, numbering about 150 species. 

Species of Phlox, Oilia, PoUmonium, Cohosa, etc., are cultivated in 
flower gardens. 

583.— Cohort XV. Gentianales. Plants with opposite 
leaves, regular flowers, superior ovary, and the stamens usu- 
ally as many as the corolla lobes and alternate with them. 

Order Gentianacese. — The Gentian Family. Annual or perennial 
herbs, with a watery juice ; ovary generally one-celled, with many 
ovules. The species, of which there are about 500, are found mostly 
in temperate and cold climates. They possess a bitter principle, which 
has been employed in medicine. We have many very pretty wild 
species. 

Order Loganiaceee. — Woody plants almost entirely of the tropics, 
with two-celled ovaries. About 350 species are known ; they contain 
a bitter principle which is often exceedingly poisonous. 

Strychnos nux-vomica is a small tree of India, bearing an orange-like 
fruit containing numerous large flatfish seeds (2 cm. in diameter). 
These seeds constitute the poisonous drug, Nux Vomica ; they con- 
tain two alkaloids to which their activity is due, viz , Strychnia 
(C21 H22 N2 O2) and Brucia (C23 H26 N2 O4 + 4 H2 0). The ordinary 
form of the first as found in the shops is a Sulphate of Strychnia. 

S. toxifera, a tree of the northern parts of South America, yields 
from its bark and young wood the famous poison known as Curare, 
Urari, Ourari, Woorara, etc. 

S. Tieute, a Javanese climber, furnishes the virulent Upas Tieute 
or Tjettek with which the natives poison their arrows. 

Order Asclepiadacese. — The Milkweed Family. Woody or herba- 
ceous plants, with a milky juice; ovaries two, distinct, but with a 
single common stigma; pollen agglutinated into masses (pollinia). 
This large order of about 1300 species is chiefly tropical, being abun- 
dantly represented in America, Africa, and Asia. The milky juice con- 
tains Caoutchouc, and usually acrid and poisonous principles. But few 
of the species are of sufficient economic importance to demand notice. 
Many have a local reputation as domestic medicines. (Figs. 428-32.) 

Some are favorites in the flower garden or conservatory, 6.^., the Wax 
Plant of India {Hoya carnosa), species of Geropegia, Stephanotis, Peri- 
ploca, etc. The South African Stapelias resemble Cacti, being fleshy 
and leafless 

The peculiar structure of the flowers in this order has recently been 
shown to be for the purpose of securing the services of insects in the 
process of pollination. 



506 BOTANY. 

juico, and mostly diclinous flowers. About 250 species are known in 
this order, the greater part occurring within the tropics. 

Dios2^yros reticulata, a large tree of the island of Mauritius, produces 
the best of the timber known as Ebony. Ebony is also derived from 
D. Ehenum and D. melano'xylon of Ceylon, and B. Ebenaster of the 
Calcutta region. 

B. hirsuta, of Ceylon, produces the beautiful " Calamander Wood,'* 
which is variegated with brown and yellow stripes. 

B. Kaki, a Chinese and Japanese tree, bears plum-like fruits which, 
are delicious. In our markets they are known as Chinese Dates. 

B. Virginiana, the Persimmon of the Southern United States, pro- 
duces fruits similar to the last, but astringent and inedible until after 
being frosted. Doubtless under culture this fruit might be made to 
equal the preceding. 

Order Sapotacese. — Plants with a milky juice and monoclinous 
flowers. A tropical order of about 800 species, a few of which extend 
into temperate regions. 

Isonandra gutta, a large tree of the Malay Islands and Borneo, is the 
source of the Gutta Perclia of commerce. The milky juice is collected 
and evaporated, and then constitutes the crude Gutta Percha. 

Chrysophyllum Cainito, the Star Apple, Archas sapota, the Sapodilla 
Plum, and Archas mamTnosa, the Marmalade, are West Indian trees, 
which bear delicious pulpy fruits. 

Bassia hutyracea acd B. iatifolia, both of India, and B. Parkii, of 
tropical Africa, are called Butter Trees, on account of the butter-like 
fatty substance obtained from their seeds by pressure. 

We have eight species within the United States, round mostly along 
our Southern coast. Two species of Bumelia reach the Ohio River. 

585.— Cohort XVII. Primulales. — Plants with mostly 
alternate leaves, regular flowers, and superior one-celled 
oyaries ; stamens generally opj)osite to the corolla lobes . 

Order Myrsinaceae. — Trees or shrubs, mostly of the tropics. Three 
or four species barely reach the southern part of Florida. 

Order Primulacege. — The Primrose Family. Herbs mostly with 
radical leaves ; placenta central, free and globose ; ovules many, fixed 
by their ventral face. Species 250, mostly of the North Temperate 
Zone. (Figs. 433-5.) 

The order is chiefly valuable for its ornamental plants. 

Primula zulgaris, the Primrose, and P. veris, the Cowslip, are com- 
mon English plants, often referred to in poetry. 

P. Sinensis, the Chinese Primrose, and P. Auricula, the Auricula 
from Southern Europe, are common in gardens and green-houses. 

Cyclamen, Bodecatheon, and Bysimachia contain fine ornamental 
species. 



PBIMULALES. 



507 



Anagallis arvensis is a little weed from Europe. 

Order Plantaginacese. — The Plantain Family. Herbs, mostly with 
radical leaves ; placenta central, not free ; ovules usually many, fixed 
by their ventral face. This anomalous order appears to be more at 
home in this Cohort than anywhere else. It disagrees with the charac- 
ters given for the Cohort in its ovary being for the most part two-celled. 



Figs. 433-5.— IiiLUSTKATioNS op Anagallis arvbnsis. 

^^mivm /r. 

A 





Fig. 434. 




Fig. 433. 



Fig. 435. 



Fig. 433.— Section of youna; flower-bud. I, calyx ; c, corolla ; a, stamens ; K, pis- 
til ; S, placenta. B, gyncecium further advanced. G, gynoecium ready for fertiliza 
tion. D, young fruit. (After Sachs.) 

Fig. 43i.— Ripe fruit. Magn fled. 

Fig. 435.— Dehiscent fruit. Magnified, g^ seeds. 

Otherwise its ao^reement is so marked as to allow us to regard it as a 
group of degraded Primulales. The species number about fifty, and 
are found in all temperate regions. 

Planto,go major, the common Plantain, is found everywhere in door- 
yards. 

Order Plumbaginaceee. — Herbs or barely woody plants, with 
leaves radical or cauline ; ovary one-celled, one-ovuled. About 200 
species are known, distributed throughout temperate climates. 



508 



BOTANY. 



Armeria vulgaris, Thrift, of Europe, is cultivated in flower-gardens. 
Plumbago; several South African and East Indian species, are to be 
met vv^ith in conservatories. 

586.— Cohort XVIII. Ericales. — Plants with regular 
flowers, and superior two to many-celled ovaries ; stamens as 
many or twice as many as the corolla lobes, hypogynous or 
epipetalous. 

Order Lennoacese. — Californian and Mexican leafless root-parasites. 

Order Diapensiacese. — Low plants (six to eight species) of North 
America and Eastern Asia, of much botanical, but no economic interest. 

Order Ericaceae. — The Heath Family. Mostly shrubs or small 
trees, a few herbs, with usually alternate, simple, and entire leaves ; 
ovary mostly five-celled, with placentae in the axis ; anthers opening 
by a terminal pore, rarely by a lateral slit; pollen grains compound, 
rarely simpiC. 

Under these characters are included about 1700 species, which ar» 
often regarded as constituting five orders, viz., Ericiiieae, Epacrideae, 
Pyrolinese, Monotropeae, and Vacciniese, here to be considered as sub- 
orders. While, however, there are considerable differences between 
the plants here brought together, they are not important enough to 
counterbalance the many evident resemblances. The relationship sub- 
sisting between the sub-orders may be shown as follows : 

VACCINIE^. 
77 (Ovary inferior.) 



EPACRIDE^. <- 

f Stamens epipetal- ") 
J ous or hypogyn- ! 
1 ous ; anthers I 
[with a slit. J 



-ERICINE^- 




f Gamopetalous ; 
ovary superior ; 
stamens hypogyn- 
ous ; anthers 
with a pore ; pol- 
1 e n grains com- 

[ pound. 



PYROLINEiE. 
(Choripetalous.) 



MONOTROPEiE. 

j Choripetalous; anthers with a) 
I slit ; pollen grains simple. ) 



EBICALES. 



509 



Figs. 436-9.— Illustrations of Erica cinerea. 



Tlie Ericinese are doubtless to be regarded as the central or main 
jrroup, from which the others have diverged. In the diagram the dis- 
tinguishing characters which are given for Ericinese may be regarded 
as typical for the order, and under eacli of the other sub-orders are 
given the exceptional characters, or more properly, the modifi3ations of 
the original ordinal characters. 

Suh-Orcler Ericinece, — About 1000 species of shrubs, many 
evergreen. Many are 
of great beauty, and are 
extensively grown as 
ornaments ; others are 
good-sized trees, and 
furnish valuable tim- 
ber. (Figs. 486-9.) 

Arbutus Menziesii, 
the Madrona of the Pa- 
cific coast of the Unit- 
ed States, is an ever- 
green tree twenty-four 
to thirty metres (80 to 
100 ft.) in height. Its 
hard wood is useful in 
furniture-making. 

Arctostaphylos pun- 
gens and A. glauca are 
large evergreen shrubs 
of California, which 
bear the name of Man- 
zanita. The heavy, 
dark-colored, and fine- 
grained wood is used in 
turnery and furniture- 
making. The berries 
are eaten by grizzly 
bears. 

A. Uva-ursi, the 
Bearberry of the colder 
portions of North 
America, Europe, and Asia, bears bitter and astringent leaves, which 
are oflBcinal. 

Calluna vulgaris, the Common Heath of Central and Northern Europe, 
is a low, straggling evergreen under-shrub. Its stems are made into 
brooms, and its flowers aflbrd an abundance of excellent honey. It 
occurs in a few scattered localities in Massachusetts, Maine, Nova 
Scotia, and northward, but it is doubtful whether it is really indigenous 
to any part of the United States. 




Fig. 438. 



Fig. 439. 



Fig. 436.— Flowering stem. 

Fig. 437.— Section of flower. Magnified. 

Fig. 438.— Diagram of flower. 

Fig. 439.— Section of ovary. Magnified. 



510 BOTANY. 

Epigcea repens, the Mayflower or Trailing Arbutus, is a low trailing- 
plant witli a woody stem, found chiefly in New England and adjacent 
reorions. Its rose-colored fragrant flowers, wliicli appear in early 
spring, are much sought for. 

Erica. This large genus, including 400 or more species, is distrib- 
uted in Europe, Northern Asia, and Northern and Southern Africa, 
reaching its maximum in the latter region. None are found in 
America. Many species are grown in conservatories. 

Gaultheria procumhens, Wintergreen or Checkerberry, has aromatic 
fruit and foliage. From the latter an officinal oil is distilled. 

Kalmia. A genus of beautiful plants with curious flowers ; each 
stamen when the flower opens is bent backward, and its anther is 
hidden in a sac in the corolla ; somewhat later the anthers escape from 
the sacs and the pollen is ejected. This mechanism has probably to 
do with the process of cross-fertilization through the agency of insects. 
Some of our native species are reputed to be poisonous to domestic 
animals, e.g., K. angustifolia, the Sheep Laurel or Lambkill. 

Rhododendron. This genus is now made to include the Azaleas as 
well as the true Rhododendrons. Some species become large trees {R. 
arboreum of the Himalayas), while many are highly prized as orna- 
mental shrubs. The Great Laurel {R. 7naxi7num), a, shrnh or small tree, 
with large evergreen leathery leaves, grows in the Alleghany Moun- 
tains. R. Catawhiense and its hybrids with R. arboreum are extensive- 
ly planted for ornaments. R. Indica is the Azalea of the florists ; it 
has many varieties. 

Huh- Order Epacridece, — About 320 species of shrubs or small 
trees, often with a Heath-like appearance ; natives of Australia and 
many of the Pacific islands ; only one species is found in South Amer- 
ica. Many species are grown in conservatories, e.g., Epacris, Leucopo- 
gon, DracopTiyllum, etc. 

Stlb-Order Pyrolinece, — Perennial herbs, about twenty species, 
all of the North Temperate Zone. They are of but little account 
economically or otherwise. Ghimaphila maculata, Pipsissewa or 
Prince's Pine, was used by the Indians as a medicine. The dried 
leaves constitute the officinal drug Ghimaphila. 

The anomalous genus Clethra, including twenty-five species of shrubs 
and trees (American and Asiatic) is sometimes placed in this sub-order 
on account of its choripetalous corolla ; it appears, however, to prop- 
erly fall into the Ericinese, in either the tribe Andromedese or Rho- 
dorese. 

Sub-Order Monotropece, — Small herbs, parasitic or sapro- 
phytic, destitute of chlorophyll ; their leaves are reduced to mere 
bracts, and their flowers and seeds show still further degradation. Ten 
or twelve species are known, distributed throughout the temperate 
parts of the Northern Hemisphere. 



GAMPANALES. 



511 



Illustrations of Vaccinium Myb- 

TILLUS. 



Monotropa uniflora, Indian Pipe, is common tliroughout nearly all 
North America, It appears to be saprophytic. 

Sar codes sanguinea is the interesting Snow Plant, which in the 
Sierra Nevada Mountains of California shoots up its flesh-red stem 
and flowers in early spring, soon after the snow melts. 

Sub-Order Vacciniece, — Shrubby plants, mostly of the North- 
ern Hemisphere. Species, 320. The thick adherent calyx-tube of the 
flower often becomes fleshy and edible in fruit. (Figs. 440-41.) 

Oaylussacia resinosa, a low shrub of the Eastern United States, pro- 
duces the Black Huckleberries of the markets. 

Vaccinium Pennsyhanicum, the Early Blueberry, or Blue Huckle- 
berry, and V. vacillans, the Low or Late Blueberry, are common in the 
Northeastern United States. 

V. cory mbosum, the Swaui-p Blueberry, is also common in the Eastern 
United States. Be- 
sides these, other spe- Figs. 440-41. 
cies furnish edible 
fruits which are some- 
times found in the mar- 
kets. V. Myrtillus oc- 
curs with us only in the 
Kocky and Sierra Ne- 
vada Mountains. 

V. Oxycoccus, the 
Small Cranberry of the 
Northeastern United 
States, and the much 
larger var. macrocar- 
pon, or Large Cran- 
berry, which extends 
much further south, 

are valuable for their acid fruits. The variety is extensively culti- 
vated from Massachusetts to Wisconsin. 

587,— Cohort XIX. Campanales. Plants with flowers 
mostly zygomorphic ; ovary inferior, two- to six-celled (rarely 
one-celled) ; ovules usually many in each cell. 

Order Campanulaceas. — Herbs, rarely shrubs, usually with alter- 
nate leaves and a milky juice, ovary two- to many-celled. The 1000 
species which compose this order were until recently divided between 
the two orders Lobeliaceae and Campanulacea), which are here merged" 
• into one. The order as now constituted is represented in all regions, 
but most abundantly in temperate ones. All possess more or less 
acridity, which in some cases becomes a dangerous poison. 

I Lobelia inflata and L. sypJdlitica of the Eastern United States have* 
been used in medicine ; now principally used by quacks. 
; 




Fig. 440. 



Fig. 441. 



Fig. 440.— Flower. 

Fig. 441.— Section of flower. 



Magnified. 



Magnified. 



512 BOTANY. 

L. cardinalis, the Cardinal Flower, of the Eastern United States, 
and several foreign species, are showy plants in the flower-garden. 

Campanula medium, Canterbury Bells, and other European species, 
are in common cultivation. 

Order Goodeniacese. — Mostly Australian, herbaceous plants, num- 
bering about 200 species, of but little economic value. 

Order Stylidiaceae. — Curious herbs, about 100 in number, mostly 
Australian. Species ot Stylidium are grown in conservatories. 

588.— Cohort XX. Asterales. Plants with actio omorphic 
or zygomorphic flowers ; stamens inserted on the corolla and 
isomerous with its lobes ; ovary inferior, one-celled, one- 
ovuled (rarely two- to three-celled). Calyx limb often greatly 
reduced, forming a pajopus, sometimes wanting. 

Order Compositse. — The Sunflower Family. Herbs, shrubs, or 
rarely trees ; anthers united to each other ; ovary, one-celled, contain- 
ing a single erect seed destitute of endosperm. In this immense 
family of fully 10,000 species, distributed throughout all parts of the 
world, the small flowers are gathered into compact heads, which them- 
selves often resemble single flowers. Many of the species are of great 
beauty, and are greatly admired as ornaments, but it is curious to 
observe, that despite the great size of the order, there are but few 
plants which are otherwise of any considerable use to man. Many are 
troublesome weeds. 

In Bentham and Hooker's " Genera Plantarum," the 766 genera are 
arranged under thirteen tribes, as given below. 

Tribe 1, Cichofiacece. — Flowers all ligulate ; juice milky. 

Cichorium Intyhus, Chicory, of Europe, is much cultivated in France 
and Germany. Its roots are used to adulterate coffee. G. Endima^ of 
India, is the Endive, cultivated in gardens as a salad plant. 

Lactuca satica, the Garden Lettuce, is probably a native of Asia. 
The dried juice of L. mrosa, of Europe, constitutes the narcotic drug 
Lactucarium. 

Taraxacum Dens-leonis, the Common Dandelion, is used somewhat 
in medicine. (Figs. 442-5.) 

Tragopogon porrifolius, Salsify, of Europe, is cultivated for its 
edible root. 

Tribe 2c Mutisiacece, — Flowers usually bifid, ^.e., two-lipped. 
We have but one representative, Ghaptalia tomentosa, in Southeastern 
United States. They abound in tropical America. 

Tribe 3, Cynaroidece, — Flowers all tubular. 
Gynara 8colymus, a native of the Mediterranean basin, is the Arti- 
choke, grown for the thick scales of its flower heads, which are edible. 
Garthamus tinctoria, a Chinese annual, is grown in gardens for its 



ASTER ALES. 



513 



red flowers, which are gathered and dried, constituting tbe dje Saf- 
fiower. 

Centaurea odoraVt and G. moscliata, from Asia, and other European 
and American species, are cultivated in flower gardens. 

Cnicus includes our Thistles, most of which are weeds in fields. 

Figs 442-5.— Illustrations op Taraxacum Dens-leonis. 




FiQ. 442. 



Pig. 443. 



FiQ. 445. 



Fig. 443.— Head of flowers, with a bud on the right, a closed fruiting head on the 
left, and two leaves. 
Eig. 443.— Flowt-r Magnified. Fig. 444.— Receptacle and fruits. 

Fig. 445.— Fruit. Mai^nilficd. 



L(7. arvensis, the so-called Canada Thistle, is in reality an Old World 
species. It is one of the most difficult of all our weeds to eradicate on 
iccount of its undero^round stems, which are tenacious of life. 
lanceolatus, the Common Ttiistle, is another introduced species. 



514 BOTANY. 

C. pumihiR, tlie Pasture Thistle, and C. horridulus, tLe Yellow Thistle, 
are indigenous. 

Tribe 4. Arctotideee, — Flowers partly tubular (forming a central 
disk), and partly ligulate (forming rays to the head). Natives of 
Africa and Australia. 

Tribe 5. Calendulacece. — Similar to the preceding. Natives 
mostly of Africa and Asia. 

Tribe 6*. S'fiecionidece, — Heads mostly with disk and ray flow- 
ers. 

Arjuca montana, a perennial of Europe and Siberia, from which the 
officinal Arnica flowers and roots are derived. 

Senecio scandens, of the Cape of Good Hope, is cultivated as a liouse 
plant under the name of German Ivy. 

Many other species of this genus are cultivated — e.g. , the so-called 
Cinerarias, Cacalia, Farfugium, etc. Some of the species are common 
weeds. 

Bedford ia snlicina, a native of Tasmania, attains a height of four to 
five metres (15 ft.). Its wood is hard, and is much prized for cabinet 
work on account of its beautiful grain. 

Tribe 7 » Ailtheniidece, — Heads mostly with disk and ray flow- 
ers. 

Artemisia AbsintJuum, tlie Common Wormwood of Europe, is cul- 
tivated in old gardens as a domestic remedy. In Europe an alcoholic 
extract called Absinthe is u?ed as an intoxicating beverage. Some 
species in the Rocky Mountain region are tall shrubs, and are called 
Sage Brush. They furnish a valuable fuel. 

AntJiemis nohilis. Chamomile, and Tanacetum vulgare. Tansy, of 
Europe, are well known domestic herbs. 

Chrysanthemum roseum, from Persia, C Indicvm, from China, and 
C. coronarium, from North Africa, are the originals of the Chrysanthe- 
mums so common in flower-gardens. 

C. Leucanthemum, the Ox Eye Daisy, is a most diflScult weed to eradi- 
cate. 

Tribe 8. Helenioidece. — Heads mostly with disk and ray flowers. 

To this belong the so-called French or African Marigolds, Tagetes, of 
several species, cultivated in flower gardens. They are in reality na- 
tives of tropical America. 

Tribe 9, Helianthoidece.— Reads mostly with disk and ray 
flowers. 

Dahlia variabilis and one or two other species from Mexico, are the 
original forms of tlie Dahlias of the flower-gardens. 

Zinnia elegans, of Mexico, is the well known Zinnia of the gardens. 

Coreojjsis, of several Arkansas and Texas species, are grown under 
the name of Calliopsis. 

Ilelianthus annuus, tlie Common Sunflower, is a native of the Texan 
and ^lexican regions. Aside from its ornamental use, its oily seeds are 



ASTERALE8. 



515 



valuable for fattening poultry, and tlie dried stems are good for fuel. 
In Russia a valuable oil is obtained from tlie seeds. 

H. tuberosus, the so-called Jerusalem or Brazilian Artichoke, la 
mucli grown for its potato-like tubers, which are fed to cattle and swine. 
It is probably derived from H. doronicoides, of the Mississippi Valley, 
by long cultivation. The name " Jerusalem " Artichoke is a corruption 
of the Italian Girasole — i.e., sunflower. 

Among the weeds are the Ragweeds {Ambrosia), Cockleburs {Xan- 
thium), Spanish Needles (Bidens). 

Silphium laciniatum is the Compass Plant of the Mississippi Valley. 

Figs. 446-50. — Illustrations op Eupatorium. 




Pig. 447. 



Fig. 448, 



Fig. 446.— Head of flowers. 
Fig. 448.— Flower. Magnified. 
Fig. 450.— Pistil. Magnified. 



Fig. 447.— Diagram of flower. 

Fig. 449.— Section of flower. Magnified. 



Its large erect pinnately lobed leaves twist upon their petioles so as to 
present one surface of the blade to the east and the other to the west, 
the two edges being upon the meridian. (Fig. 184, p. 157.) 

Tribe 10, Inuloidece, — Heads mostly with disk and ray flowers. 

Helipterum Manglesii, of Australia, is one of the " Everlasting flow- 
ers," cultivated under the name of Rhodanthe, and used for winter 
bouquets. 



510 BOTANY. 

nelichrysuin, sp., is also cultivated for tho same purpose. 

Iiinla HeLetiium, Elecampane, of Europe, is cultivated in gardens for 
its medicinal root. 

Tribe 11, Asteroidew.—TieaidB mostly with disk and ray flowers. 

Aside from our native species of Aster and iSolidaffo (Golden Hods) 
which. &Te 0TnQ.ment3i\, Bellis perennis, the English Daisy, and Callis 
tephns Chinensis, the China Aster, are common in flower-gardens. 

Orindelia rohusta and other species are important as furnishing in 
the alcoliolic infusion of their leaves a cure for the poisoning by Poison 
Ivy. 

Olearia argophylla, the Musk Tree of Tasmania, attains a height of 
six metres (20 ft.) and a diameter of thirty cm. (1 ft.). Its wood is hard, 
and is used in turnery and in the manufacture of agricultural imple- 
ments. 

0. furfuracea and several other New Zealand species are equally 
valuable. 

Tribe 12, Eupatoriacece, — Flowers all tubular. (Figs. 446-50 ) 

Species of Eupatorium are used as domestic medicines. Several of 
the species are ornamental. 

Mikania scandens, a native climber, is cultivated for ornament. 

The native species of Liatris, Blazing Star, are also quite orna- 
mental. 

Tribe 13. Vernoniacece. — Flowers all tubular. 

The species of Vernonia, known by the name of Iron-weed, are com- 
mon weeds on low grounds. 

Order Calyceracese. — A few South American herbs resembling 
Compositse, but with the ovule pendulous. 

Order Dipsaceae. — Herbs, with distinct anthers and pendulous 
seeds, which contain endosperm. Species one hundred and twenty, 
mostly of the North Temperate Zone. 

Dipsacus Fullonum, Fuller's Teasel, of Europe, is grown for itshard- 
bracted ripe heads, wliich are used by fullers in dressing woolen cloth. 

Scabiosa contains many ornamental species. 

Order Valerianaceae. — Herbs, with distinct anthers, and three- 
celled, but (by absorption) one-seeded ovary ; seed without endosperm. 
Species about three hundred, mostly of the North Temperate Zone. 

Valeriana officinalis, of Europe, has a thickisH root, which, in the 
dried state, is the ofl&ciual Valerian. 

589.— Cohort XXI. Rubiales. Plants with actinomorph- 
ic or zygomorphic flowers ; stamens inserted on the corolla 
and isomerons with its lobes ; ovary inferior, two- to many- 
celled, each cell with one to many oYules. Calyx never 
pappose. 
• Order Rubiaceee. — Herbs, shrubs, and trees ; flowers generally reg- 



RUBIALE8. 



517 



ular (actinomorphic) ; leaves witli stipules. A large order of over 4000 
species, the greater part of which inhabit tropical countries. It is 
divided into twenty-five tribes, many of which difier so greatly from 
each other that they have been regarded as orders by some botanists. 

The most common representatives of this order in the United States 
are the species of Galium (Bedstraw or Cleavers), Mitcliella (Partridge 
Berry), and Houstonia (Bluets). 

Ceplialanthus occidentalis, the Button Bush of the Eastern United 
States, is a tall shrub bearing glossy green leaves and spherical heads 
of white, sweet-scented flowers. It deserves to be ranked among our 
ornamental shrubs. 

Pinckneya pubens, a small tree of the Southeastern United States, is 
known as Georgia Bark, or Fever Tree, on account of the medicinal 
qualities of its bark. 

Cinchona, of several species. This South American genus contains 
thirty or more species of trees ; several of these, as G. officinalis, C.cali- 

FiGS. 451-5.— Illustrations or Coffea Ababica. All Magnified. 




Pig. 451. 



Fig. 452. 



Fig. 453. 



Fig. 454. 



Fig. 455. 



Fig. 451. — Berry. Fig. 452.— Seed ; ventral face. 

Fig. 453.— Seed ; dorsal face. Fig. 454.— Transveree section of seed. 

Fig. 455.— Dorsal face of seed, cut away to show embryo. 



saya, G. succiruhra, etc., all natives of the Andean regions of Peru, 
Bolivia, and New Granada, furnish the drug known as Peruvian 
Bark. This bark contains two important alkaloids, viz. : Cinchonia 
(C20 H24 N2 0), and Quinia (C20 H24 N2 O2 + 3 H2 0) ; the latter as a 
sulphate is the exceedingly valuable medicine, Quinia Sulphate, or 
Quinine. Cinchona trees are now cultivated in India, Java, Mauritius, 
and Jamaica. 

Cephaelis Ijyecacuanha, a semi-shrubby plant of Brazil, supplies from 
its roots the well-known emetic Ipecacuanha. 

Coffea Arahica, the Coffee Tree, a native of Abyssinia, is a small- 
sized evergreen tree, bearing clusters of white flowers in the axils of 
the opposite glossy leaves. The red berries are about as large as 
cherries, and each contains two plano-convex seeds, the coffee seeds of 
commerce (Figs. 451-5). The Coffee tree was introduced into Arabia 
from four to five centuries ago, and into Java, by the Dutch, about 
two centuries ago. It has since been taken to Brazil and other parts 



518 BOTANY. 

of Soutli America, the West Indies, Ceylon, India, and many of 
the Pacific islands. Although originally from the same species, the 
Coffee trees now grown in different parts of the world produce seeds 
varying much in size, color, and quality; thus in "Mocha," from 
Arabia and Abyssinia, the seeds are small, of a dark yellow color, and 
when roasted produce an infusion of a most delicious quality ; in " Java 
coffees " the seeds are larger, of a paler yellow color, and of scarcely in- 
ferior quality to the preceding ; the coffees of Ceylon, West Indies, and 
Brazil (the latter particularly known as " Rio ") have seeds of vary- 
ing sizes, and of a bluish or greenish-gray color, and their infusions 
are generally inferior to those of the other varieties. 

Ruhia tmctoria, a perennial herb, native of the South of Europe and 
Western Asia, is the Madder Plant, now grown in many parts of the 
world for its roots, which yield the red dye known as Madder. The 
plant has whorled leaves and bears some resemblance to some species 
of Galium. 

Among the ornamental plants of the order are many species of Gdr- 
denia from China and Africa, Ixora, Portlandia, Bouvardia, etc. 

Order Caprifoliaceae. — Mostly woody plants, with generally zygo. 
morpliic flowers and stipulate leaves. This small family of two hun- 
dred species is mostly confined to the Northern Hemisphere, A dras- 
tic and purgative principle is common in the plants of the order, but 
none of the species are of much importance in medicine. Many species 
are ornamental — e.g., those of Lonicera, the Honeysuckles ; Symphori- 
carpus, the Snowberries ; Biermlla, the Bush-Honeysuckles, one spe- 
cies from Japan called Weigelia ; Viburnum, the Snowball, etc., etc. 

Sambucus, the Elder, has edible berries, which are much used for 
making into pies, preserves, jellies, wine, etc., in many parts of the 
United States. 

III. CHOEIPEa^AL^ (PoLTPETAL^ of authors). Plants 
whose flowers generally liaye both calyx and corolla, the lat- 
ter of separate petals. 

590.— Cohort XXII. Umtoellales. — Flowers usually actin- 
omorphic ; ovary inferior, one- to many-celled ; ovules soli- 
tary, pendulous ; seeds with endosperm. 

Order Cornacese. — The Dogwood Family. Shrubs or trees, rarely 
herbs, with mostly opposite simple leaves ; fruit a berry or drupe. A 
small order of about seventy-five species, mostly of the north temperate 
zone. 

Several native and European species of Cornus are cultivated as orna- 
mental shrubs. 

Aucuha Japonica. from Japan, is a fine shrub of the flower-gardens. 

The wood of Cornus florida, the Flowering Dogwood of the Eastern 



UMBELLALES. 



.19 



-Illustrations of Fceniculum yulgaeb. 
All. Magniplbd. 



United States, is hard and fine-grained, and is sometimes used as a sub- 
stitute for Boxwood. 

The wood of JSfyssa multiflora, the Sour Gum, Tupelo, or Peppridge 
tree of the Eastern United States, is exceedingly difficult to split, and 
is much used for making hubs for wagon wheels. 

Order Araliacese. — Shrubs or trees, rarely herbs, with mostly al- 
ternate compound leaves ; fruit usually a berry or drupe. Species 340, 
mostly tropical. 

Some of the species of ^r«^i« are ornamental — e.g., A. spinosa and 
A. raccmosa, of the 
Eastern and South- Figs. 456-60.- 
ern United States. 

Hedeva Helix, the 
English Ivy of Eu- 
rope and Western 
Asia, is a well- 
known ornamental 
climber. 

Aralia quinquefo- 
lia, Ginseng, is com- 
mon in many parts 
of the Eastern 
United States. Its 
root is officinal. 

Aralia papyrife- 
ra, a small tree of 
China, is the source 
of the Chinese Rice 
paper ; for this pur- 
pose the pith is cut 
into thin sheets and 
then pressed flat. 

Order TJmbellif- 
srse. — Herbs, rarely 
shrubs or trees, with 
ilternate and usual- 
ly much dissected leaves ; fruit dry and indehiscent. Species 1300, 
found most abundantly in Northern Europe and Asia, although occur- 
ring in nearly all countries. Many contain an acrid poisonous princi- 
ple, and the plants of the order may usually be regarded with suspi- 
cion. In a general way it may be said that the fruits are aromatic 
md innoxious, and the green parts acrid and poisonous. (Figs. 456-60.) 

The Parsnip (Pastinaca satim) and the Carrot {Daucus Carota), 
both natives of Europe, are valuable and well-known food plants, 
[n tlieir wild state they are poisonous. 

Apium graveolens, Celery, a native of Europe, is deservedly popular 







Fig. 458. 



Fig. 456. 
Fi?. 458. 
Fig. 460.- 



-Flower. 

-Flower diagram. 
-Section of seed. 



Fig. 459. 

Fig. 457.- 
Fig. 459.- 



FiG. 460. 

-Section of flower. 
-Ripe fruit. 



520 BOTANY. 

as a salad. The poisonous herbage, when deprived of its green color by 
covering with earth, is rendered wholesome. 

Among the aromatic and medicinal products may be mentioned Cara- wk 
way, Coriander, Cummin, Fennel {Foeniculum vulgare), Dill, Aniseed, !f 
etc. 

Ferula Asafo&tida is a tall growing plant of Thibet and the western 
parts of Asia. The dried and hardened milky juice of the root is the 
nauseous smelling Gum Asafoetida. It is said that the Persians hold 
it in high esteem as a condiment. Gum Ammoniacuni,GumGalbanum, 
Gum Opopanax,and some other gum resins are similar strong smelling 
products of other plants of the same region. 

Coniiim maculatum, Poison Hemlock, a native of Europe, but 
naturalized in the United States, is virulently poisonous. It is sup- 
posed to be the Hemlock used by the Greeks to poison their criminals 
and other offenders. 

Cicuta maculata, Water Hemlock, and ^thusa Cynajpium, Fool's 
Parsley, are two common poisonous plants, the first a native of the 
Eastern United States, the second introduced from Europe. 

Monizia edulis, of the Madeiras, is a low tree, and in Australia spe- 
cies of XantJiosia, Trachymene, Astrotrichia, etc., are shrubs or small 
trees. 

591.— Cohort XXIII. Ficoidales. Mowers usually actin- 
omorpliic ; ovary mostly inferior, one- to many-celled ; pla- 
centae parietal, basilar or axile ; seeds with or without endo- 
sperm. 

Order Ficoidese.— Mostly herbs, often with fleshy leaves. Species 
450, mostly tropical, represented in the United States by the Carpet- 
weed {Mollugo 'vertidUata). 

Mesembryanthemum crystallinum, the Ice Plant, is commonly culti- 

vated as a curiosity. 

Order Cactacese.— The Cactus Family. Succulent herbs, shrubs, 
or trees, often spiny, and generally leafless. About 1000 species are 
enumerated, all American (with one or two exceptions), and mostlyf 
tropical. Several of the species are common in many parts of the Okj 
World, having long since escaped from cultivation. i 

Many of the species are grown in conservatories for their fine flow 
ers, as well as on account of their curious shapes. Cereus grand%\ 
florus, the Night Blooming Cereus ; Opuntia vulgaris, the commoi 
Prickly Pear ; 0. coccinellifera, and others, are common. The last 
named is fed upon by the Cochineal Insect, from which the dye Carmini 
is derived. I 

The fleshy fruits of some species are edible. i- 1^ 

592.-Cohort XXIV. Passiflorales.— Flowers usually m JjJ 

tinomorphic ; oYary usually inferior, syncarpous, one-celled ,^^^_ 






PASSIFL OR ALES. 



521 



with parietal placentae (sometimes tliree or more celled by 
the produced placentte). 

Order Datiscaceas. — A curious order of four species, one of which, 
Datisca'glomerata, occurs in California. 

Order Begoniaceae.— A tropical order of 350 species of lierbs, mostly 
Figs. 461-5.— Illustrations of Cucu3iis Melo. 





Fig. 464. 



Fig. 465. 



Fig. 461.— Male flower, vertical section. 

Fig. 462. — Female flower, vertical section. Fig. 463.— Androecium. Magnified. 

Fig. 464.— Diagram of male flower. Fig. 465.— Diagram of female flower, 

American, represented in green-houses and conservatories by many 
species of the principal genus Begonia — e.g., B. Rex, B. Evaiisiana, B. 
fuchsioides, etc. 

Order Cucurbitaceee. — The Gourd Family. Herbs or undershrubs 
""ith climbing or trailing stems and diclinous flowers ; placentae pro. 
iuced to the axis of the ovary and re vol ate. Species 470, mostly 
tropical. (Figs. 461-5.) 



o22 BOTANY, 

Cucurhita maxima, the large Winter Squash; C. verrucosa, the Crook- 
necked Squash ; and C. Pepo, the Pumpkin, are well known in cultiva- 
tion. Their nativity is unknown. Accordintr to Dr. Gray, the Pump- 
kin was "cultivated as now along- with Indian Corn by the North 
American Indians before the coming of the whites." 

Cucumis Melo, the Musk-Melon, and C. sativus, the Cucumber, are 
doubtless natives of India. 

Citimllus vulgaris, the Watermelon, is a native of India. 

Tlie dried liesh and seeds of Citrullmt Colocynthis, of the Eastern 
Mediterranean region, constitutes the poisonous drug Colocynth. 

Lagenaria vulgaris, the common Gourd, a native of Asia and Africa, 
is cultivated for its fruits, which are made into bottles, drinking ves- 
sels, etc. 

Luffa jMgyptica, the Towel Gourd of Egypt, is now grown in the 
West Indies and the Southern United States. Its fruit is somewhat 
larger than a Cucumber, and is very fibrous internally ; its rind and 
seed-s are removed, and the fibrous portion used as a bath sponge. 

EcMnocystis lobata, the Wild Cucumber or Balsam Apple of the 
Eastern United States, is a rapidly growing climber, valuable for ar- 
bors, screens, etc. 

Order Passifloracese. — The Passion-Flower Family. Trees, shrubs,. 
or herbs, mostly of the tropics. Species 250, represented in the South- 
ern United States by four or five species of Passiflora, and in conserv- 
atories by magnificent climbers of the same genus from South America, 

Carica papaya, the Papaw of tropical America, is a small tree, bear- 
ing large edible fruits. 

Order Turneracese. — Tropical herbs and shrubs. 

Order Loasacese. — Herbs of warm climates, mostly American, 

Order Samydaceae. — Trees and shrubs of the tropics. 

593. Cohort XXV.— Myrtales. Flowers mostly actino- 
morphic ; ovary usually inferior, syncarpous ; placentae in the 
axis (or apical, rarely basal) ; leaves simple, and usually entire. 

Order Onagraceae. — Herbs, shrubs, and trees, about 300 species, of 
temperate climates, represented in the United States by species of Epi- 
lohium, (EnotJiera, and other genera. In conservatories, many species 
of Fuchsia are cultivated for their beautiful flowers. They are natives 
of Mexico and South America. 

Trapa natans, a curious aquatic plant of Central and Southern 
Europe, is called Water Chestnut, and its large nut-like horned fruits 
are nutritious. T. hispinosa, of Northern India, and T. Ucornis, of 
China, are extensively used for food in their native countries. 

Order Lythracese. — Herbs, shrubs, and trees, mostly of the tropics. 



MYRTALE8. 523 

Species, 250, represented in the United States by a few small herbs of 
the genera Lythrum, Cwpliea, etc. 

Lawsonia inermis, a shrub of Western Asia, has long been in culti- 
vation in Egypt and the adjacent countries. From its leaves the cos- 
metic Henna or Klienna, so much used for coloring the hair and nails, 
is made. 

Punica graiiatum, the Pomegranate of India, is a bushy tree, six to 
nine metres high (20-30 feet), bearing deciduous leaves, and yellowish 
fruits about the size of an apple. Tlie pulpy interior of the latter is 
prized for making cooling drinks; from it a wine is also made. Pome- 
granates have long been grown in the countries about the Mediterranean 
Sea, and are now cultivated in the warmer parts of America. 

Lagerstroemia regince, the Jarool orBloodwood tree of India, is higlily 
valued for its blood-red wood, which, being exceedingly durable in 
water, is much used in shipbuilding. 

L. Iiidica, a common green-house shrub from India,is cultivated under 
the name of Crape Myrtle. 

8onnerat%a acida, an Indian tree, yields a most valuable fuel. 

Physocalymma floribunda, the Tulip tree of Brazil, yields a fine 
wood much used for inlaying. 

Order Melastomaceae. — Trees, shrubs, and a few herbs, of the 
tropics. Species, 1800. We have in the United States but one genus, 
Rhexia, represented by half a dozen species. A few are cultivated in 
green-houses. 

Order Myrtaceae. — The Myrtle Family. Trees and shrubs (rarely 
herbs), with mostly opjiosite glandular-dotted leaves ; stamens, many. 
A large and very difficult order of 1800 or more species, which are dis- 
tributed throughout the tropics and the Southern Hemisphere. 

Many of the species yield excellent fruits. 

Psidium pomiferum and P. pyriferum, of the West Indies, and P. 
VaUleyauum, of Brazil, bear apple- or pear-shaped fruits called Guavas, 
highly esteemed for dessert, and for preserving. All are now exten- 
sively grown in tropical climates. 

Eugenia mahtjccenm, the Malay Apple, and E. Jambos, tbe Rose 
Apple, both of the East Indies, furnish important fruits to the people 
of the far East. 

E. pimenta, a West Indian tree, is there cultivated for its berries, 
which are gat hered and dried before ripening, constituting the Pimento 
or Allspice of commerce. 

E. aromatica, the Clove Tree of the Moluccas, now extensively cul' 
tivated in the East and West Indies, is prized for its spicy flower-buds, 
which are gathered before opening and then dried, in which state they 
are known as Cloves. 

BerthoUetia excelsa, of tropical America, is a tree thirty to forty-fivo 
metres high (100-150 feet), bearing woody-shelled fruits, ten to fifteen 



I 



524 



BOTANY 



cm. (4-6 inches) in diameter, inside of wliicli are a number of rough 
oily seeds, the Brazil Nuts of commerce. Closely related to this is the 
Monkey Pot, whose woody-shelled fruit is dehiscent by a circular lid. 

Many of the trees of this order furnish valuable timber. 

Myrtus communis, the Myrtle Tree of Western Asia, yields a hard 
jnottled wood much esteemed in turnery. (Fig. 466.) 

Eucalyptus, sp,, the Gum Trees of Australia and Tasmania. These 
are large stately trees, often rising to the height of fifty to one hun- 
dred metres (150-300 feet), and occasionally even exceeding this. The 
timber furnished by them is in some cases of great value, being tough 
and durable, (Figs. 467-8.) 

E globulus, the Blue Gum, is now much planted in California. Its 
timber is valuable, but shrinks greatly in drying. E. marginata. " the 
Jarrah or Mahogany tree of Southwestern Australia is famed for its in- 
destructible wood, which is attacked neither by Chelura, Teredo, nor 




Fig. 466. 



Fig. 467. 



Fig. 468. 



Fig. 466.— Vertical section of the flower of Myrtus communis. Magnified. 
Fig. 467.— Vertical section of the flower bud of Eucalyptus glohnlus. Nat. size. 
Fig. 468.— Transverse section of the ovary of Eucalyptus globulus. Magnified. 



Vermes, and therefore much sought for jetties and other structures ex- 
posed to sea water, also for underground work, and largely exported 
for railway sleepers. Vessels built of this timber have been enabled 
to do away with copper-plating." {Mueller). E. resinifera, the Iron 
Bark tree supplies a very heavy and exceedingly strong timber. 
Species of Eugenia, Myrtles, etc., are grown in conservatories. 

Order Combretacese. — Tropical trees and shrubs, about 340 species. 

A few species occur in South Florida. 

Order B-hizophoracese. — Tropical trees and shrubs, about 50 spe- 
cies, the most important of- which is the Mangrove Tree of tropical 
America {Mhizopho7'a Mangle) ; it also occurs from Florida to Texas. 

594. Cohort XXVI.— Rosales. Flowers mostly actino- 
morphic ; carpels one or more, usually quite free in bud, 



BO SALES. 525 

sometimes yariously united afterwards with the calyx-tube. 




Fig. 469. 

Fig. 469. — Dioncea muscipula. Plant with flower-stalk. Natural size. 
Fig. 470 —Flower-cluster. Natural size. 
Fig. 471.— Pistil cut vertically. Magnified. 

or enclosed in the swollen top of the peduncle ; styles usu- 
ally distinct. 

Order Halorageae. — Mostly aquatic lierbs, about eiglity species. 



526 BOTANY. 

Order Bruniaceee. — A few heath-like woody plants of South Africa. 

Order Hamamelaceae. — A small order of trees and shrubs, repre- 
sented in the United States principally by the Witch Hazel {Hama- 
melisVirginica), and the Sweet Gum Tree {Liquidamber Styraeiflua). 

Order Droseraceee. — The Sundew Family. Mostly bog-herbs with 
radical gland-bearing leaves. About 110 species are known, distributed 
throughout the world. This interesting little family has attracted 
great attention on account of the insect-catching habits of its species. 

The most remarkable plant of the order is the Venus' Fly-Trap {I)io)icea 
muscipula) of North Carolina. Each leaf has a rounded blade which 
is fringed with stiff bristles (Fig. 469), and upon the surface of each half 
are three sensitive hairs which, when touched, cause the tissues of the 
upper surface of the midrib to contract suddenly, and thus to quickly 
close the leaf as a book or rat-trap is closed. An insect alighting upon 
one of these leaves is caughtby the quickly-closing sides, and is within 
a few days dissolved (digested) by an acidulous fluid exuded by the 
glands of the leaf ; it is then absorbed by the leaf, and when this is ac- 
complished the latter again opens. This plant is thus a partial sapro- 
phyte ! 

In the Sundews (species of Drosera), the leaves have stalked 
glands which are sensitive, and when these come in contact with an 
insect they cause the blade to slowly bend around it, finally enclosing 
it. Digestion and absorption then take place as in the previous case. 

Mr. Darwin has shown that the other genera of the order are also in- 
sectivorous. (See his book, "Insectivorous Plants," London and New 
York, 1875, in which 367 pages are devoted to the plants of this order). 

Order Crassulacese. — Herbs or undershrubs, usually with thick 
fleshy leaves. Species 400, found mostly in temperate climates. Many 
are in common cultivation — e.g., Bryojphyllum, the Live-leaf from 
tropical Africa ; Crassula, of many species, from the Cape of Good 
Hope ; Cotyledon, of many species, from Mexico and Africa ; Sedum, 
Live-forever ; Sempermvum, the Houseleek, etc. 

Order Saxifragacese. — The Saxifrage Family. Trees, shrubs, and 
herbs with actinomorphic flowers, generally definite stamens, and 
seeds rich in endosperm. Species 540, mostly natives of temperate and 
cold climates. 

Ribes grossularia, the Gooseberry, and K riibrum, the Red Currant, 
both of Europe, are in common cultivation for their edibld berries. 
The last named is also indigenous northward in this country. 

Among ornamental plants are PMladelphus, the Mock Orange, from 
the Old World ; Ribes, Flowering Currants, of the Western United 
States ; Deutzia, from China and Japan ; Hydrangea, Japanese and 
native; Astilbe, from Japan ; Saxifraga sarmentosa, the so-called Straw- 
berry Geranium, a fine basket plant from China. 

Cephalotus follicularis, the Australian Pitcher Plant, is now regarded 



B08ALE8. 



527 



as a member of this order. It is a low plant witli a rosette of radical 
leaves, some of which resemble the covered pipes used by many 
Frenchmen (Fig. 472). The border of the ascidium (pitcher) in the lat- 
ter is incurved and presents an obstacle to the egress of insects, which 
are no doubt thus captured. 

Order Rosaceee. — The Rose family. Herbs, shrubs, and trees, 
usually with actinomorphic flowers, generally indefinite (many) 
stamens, and seeds destitute of endosperm. Species, 1000, distributed 
throughout the world. The plants here under consideration have been 
arranged under several orders by some authors, on account of a part 
having an apparently inferior 5-celled ovary, others many superior 
ovaries, and still others 
but one superior ovary. 
Bentham and Hooker 
have arranged the sev- 
enty-one genera under 
ten tribes, eight of 
which only will be no- 
ticed here. 

Tribe Pomece, — 

Shrubs and trees with, 
simple leaves, ovaries 
5 (rarely less), adnate 
to and frequently cov- 
ered by tbe fleshy re- 
ceptacle (and calyx ?). 

Pirus Malus, the 
Annlp nnrl P /'nmmii Fig. 412.— LeaveB of Cephalotus folHculaHs. f, normal 
Apple, ana l^. commu- ^,^^.^1^ ^^^^ . ^„^ ascidium ; b, its incurved bdrder ; f. 
This, the Pear, grow its lid. Natural size. 

wild in many parts of Europe. They have been cultivated for ages in 
other portions of the world. (Fig. 473.) 

P. prunifoUa and P. baccata, Siberian Crab-Apples, of the North of 
Asia, are in common cultivation. 

P. coronaria, the American Crab-Apple, of the Eastern United States, 
might be made a valuable apple by cultivation. 

P. Gydonia (or Cydonia vulgaris), the Quince, is a native of the 
Levant. (Figs. 474-5.) 

The Hawthorns {Crataegus, sp.) are of some value for their fruits, 
and have long been favorites for hedges and ornamental purposes, 
Service-berries (Amelanchier, sp.) furnish valuable fruits, and are 
ornamental. 

Tribe Rosew, — Shrubs, with pinnately compound leaves ; ovaries 
many, free, but surrounded by the fleshy receptacle (and calyx?). 

Rosa — of many species— the Roses. Not only are our native species 
(of which we have about a dozen) more or less cultivated for their beau- 




628 



BOTANY. 



tiful flowers, but from eighteen to twenty or more species from 
Europe and Asia are commonly to be found in gardens and conser- 
vatories. (Fig. 476.) 

Tribe Potentillece, — Mostly herbs, with usually compound 

Figs. 473-5.— Illustrations of Tribe Pome^. 




Fig. 474. Fig. 475. 

Fig. 473.— Flower cluster of Pirus communis. 

Fig. 474.— Section of Quince flower {Fit^us Cydonia). 

Fig. 475.— Section of Quince fruit. 

leaves ; carpels free, one to many, mostly on a convex fleshy receptacle ; 
fruits dry (achenia). 
Fragaria elatior, of Europe, F. vesca, of Europe and Eastern United 



B08ALE8. 



529 



States, and F. Virginiana of the Eastern United States, are tlie species 
from which the cultivated Strawberries have been derived, by high, 
culture and crossing. (Fig. 477.) 

Chamaibatia foliosa of the western slope of the Sierra Nevada Moun- 
tains in California, is a small fragrant shrub with thrice pinnate leaves, 
much gathered by tourists, and deserving a place in gardens. 

Cercocarpus ledifolius, the 
Mountain Mahogany, of Califor- 
nia, is a shrub or tree, ranging 
from two to fifteen metres in 
height (6 to 50 feet). Its heavy 
dark colored wood is valuable. 

Tribe Rtibece, — Mostly 
shrubs, differing from the pre- 
ceding in having fleshy fruits 
(drupes). 

Ruhus IdcRus, the Garden Rasp- 
berry, of Europe, is also cultivat- 
ed to some extent in this country. 

B. occidentalism the Black 
Raspberry, and B. strigosus, the 




Fig. 476.- 
rubiginosa. 



■Section of the flower of Rosa 
Natural size. 



Red Raspberry, both natives of the 
Eastern United States, have given rise to the Common Raspberries of 
our gardens. 

B. fruticosus, the Blackberry, of Europe, is scarcely, if at all culti- 
vated in this country. B. villosus, the Wild Blackberry, of the Eastern 

United States, is exten- 
sively cultivated. 

Tribe Qiiillajem. 

— Trees and shrubs, 
with mostly simple 
leaves, dry fruits and 
winged seeds. Nearly 
all are natives of Mexico 
or South America. 

Quillaja sa'ponavia, of 
Chili, is an evergreen 
tree, fifteen to eighteen 
metres (50 to 60 feet) 
high, whose bark contains Saponin (C32 H54 Oig), and is used instead 
of soap for washing. Under the name of Soap-bark or Quillaja-bark 
it is imported into this country. 

Tribe Spirceece, — Mostly woody plants, of the Northern Hemi- 
sphere, with dry fruits. The principal genus Spircea, contains many 
species, which, being highly ornamental, are commonly planted in 
flower-o-ardens. 




Fig. 477. 
Magnified. 



-Section of the flower of Fragaria msca. 



530 



BOTANY. 



Tribe Prunew, — Trees and shrubs, witli stems yielding gum, 
simple, mostly serrate leaves, and solitary carpel ripening into a 
drupe. (Figs. 478-9.) 

Prunus communis, tlie Almond, is a native of Western Asia, and 
now grown in many warm-temperate countries for its fruits. Two 
principal varieties are grown, viz.. Sweet and Bitter ; in the former the 
kernel is edible, whereas, in the latter, it is bitter and poisonous. An 
oil is expressed from both kinds. 

The Peach has been until recently regarded as a distinct species 
(P. Persica), but it is now supposed to have been derived from the 
Almond, by long culture and selection. 

P Armeniaca, the Apricot, originally from Armenia, is now exten- 
sively grown in many countries. 

P. domestica, the Plum of Europe, P. Americana, the Common Wild 



ff^§h/n 




Fig. 478. 

Fig. 478.— Flower cluster of Prunus Cerasus. 

Fig. 479. — Section of flower of the Peacli, Magnified. 



Fig. 479. 



Plum, of the Eastern United States, and P. Chicasa, of the Southern 
States, are cultivated for their excellent fruits. The second named is 
the original form of most of the varieties grown in the central part of 
the United States. 

The Cherry, commonly referred to P. Cerasus, is probably derived 
from P. avium, the Bird Cherry, of Europe. The wood of the Bird 
Cherry is used in Europe for making furniture, as is also that of our 
Wild Black Cherry (P. serotina), of the Eastern United States. 

Many of the foregoing have, by long and careful culture, developed 
double-flowered varieties, which are sometimes to be found in gardens. 

Prunus nana, the Dwarf Almond, is well known in the double- 
flowered state. 

Tribe Chrysobalanece* — Trees and shrubs, with simple, entire 
leaves. Mostly natives of tropical America, a few of tropical Asia and 



ROSALES. 



531 



Africa. Some of tlie latter bear edible fruits. The bark of Brazilian 
trees of the genera Licania and Couepia is said to contain such consid- 
erable quantities of silica, that it is burnt by the natives and used in 
the manufacture of pottery. 

Order Leguminosae. — The Pulse Family. Herbs, shrubs, and 
trees, with alternate and usually compound leaves ; flowers for the most 
part zygomorphic ; stamens usually twice as many as the petals ; pistil 



Figs. 480-6.— Illustrations of Papilionace^. 
(480-5, Lathyrus odoratus.) 




Fig. 484 



Fig. 480.— Section of flower. Magnified. Fig. 481.— Diagram of flower. 
Fisr. 482.— Calyx. Magnified. Fig. 483.— Stamens and pistil Mag. 

Fig. 484.— Kipe fruit. Vvs. 485.— Part ol Iruit, Willi a seed. 

Fig. 486.— Section of seed of Tetragonolobus. Magnified. 

monocarpellary and free ; seeds generally wanting* an endosperm. A 
vast order of 6500 species, distributed throufjhout the world. 

The species are usually disposed in three sub-orders, each containing 
many tribes. 

Sub- Order I. Fapllionacece, with zygomorphic flowers ; sta- 
mens generally ten, monadelphous or diadelphous. This sub-order 
contains a large number of plants of great economic importance. 

The food plants include the Pea {Pivim sativum), the so-called English 
"Bean ( Vicia faba), the Pole Bean (Phaseolus vu'garis), the Field Bean 



532 BOTAJSY. 

{P. nana), the Lima Bean (P. lunatufi), probably all from India and 
Western Asia. 

Many more species are now cultivated in India, such as Chowlee, 
Black Grain, Soy, Pigeon Pea, Lentils, etc. 

The Peanut (AracMn hypogoia), a native of South America, is now an 
important food plant in the West Indies and Africa. After the fertili- 
zation of the erect yellow flowers, the peduncles bend down and the 
young pods are thrust into the ground, where they ripen. This curi- 
ous habit, which must have been at first a protective one, is perpetu- 
ated in cultivation, although the need of it apparently no longer exists. 

The forage plants include the Red Clover {Trifolium %>i'(^teuse), the 
White Clover {T. repens), Lupine (Lupinus albus), Lucerne {Medicago 
mi/^m), Sanfoin {Onohrychus sativa), Tares or Vetches {Vicia sativa), 
all from Europe and the countries adjacent to the Mediterranean Sea. 
Many others are grown less extensively. 

Of the timber trees, the following are the most important : 

Bobinia Pseud-Acacia, the Locust Tree of the Eastern United States, 
yields a very strong and durable timber. 

Dalbergia nigra, a large tree of Brazil, produces the finest Rose- 
wood. 

D. latifoUa, of India, produces the Indian Rosev^ood. 

The valuable dye Indigo is obtained from Indigofera tinctoria, a 
native of India. The flowering plants are cut and placed in vats of 
v^^ater ; after remaining for a time, the water, now colored, is drawn off, 
and after several intervening processes, the coloring matter is allowed 
to settle to the bottom ; this when dried is crude indigo. 

The wood of Ptero arpus santalinus, a tree of India, when reduced 
to chips, is the red dye known as Red Sandal-wood, or Saunders. 

Camwood, another red dye, is obtained in a similar manner from 
BapMa nitida, a West African tree. 

Some species furnish gums and balsams, which are of use in the arts. 

Gum" Tragacanth is derived from a low shrubby plant, Astragalus 
tragacantha, growing in Western Asia. 

Gum Kino is produced by large trees of India and Africa belonging 
to the genus Pterocarpus. 

Balsam of Peru and Balsam of Tolu are the products of species of 
MyroQiylon, in Central and South America. 

But one important medicinal product is furnished by this sub-order, 
viz., Liquorice, the dried roots of Glycyrrhiza glabra, a native herb of 
the South of Europe. 

In India species of Groialaria and Sesbania are extensively cultivated 
for their strong and durable fibre, much used for making cordage and 
coarse cloth. 

Of the many ornamental plants, the following only can be mentioned, 
viz., species of Lupinus, Gytisus, Laburnum, Petalostemon, Caragana. 
Bobinia, Wistaria, Phaseolus., Lathyrus, Sophora, etc., etc. 



R0SALE8. 533 

Desmodium gyrans, an East Indian plant, is remarkable for the 
spontaneous ujovements of its leaves. The leaves are compound, the 
terminal leaflet beinuf large, while the lateral ones are small ; under 
proper conditions the lateral leaflets alternately rise and fall by quick 
jerks, continuing this for hours without any apparent external cause. 

Sub-Order II, Cwsafphiiece^ with flowers zygoraor[)hic or ac- 
tinomorphic; stamens generally ten, usually distinct. 

The Tamarind is the fruit of a North Airican and East Indian tree of 
this sub-order, Tamarindus Indica. 

Senna, a medicinal drug, is the dried foliage of African and East 
Indian species of Cassia. 

Gum Copal, much used in making varnishes, is derived, at least in 
part, from East Africa and Madagascar trees belonging to the genera 
TracTiyloMum and Hymencea. 

Copaiva Balsam is obtained from Brazilian trees {Gopaifera, sp.) by 
making deep incisions into the trunks. 

The pulverized wood of Cmsalpina ecMnata, a -Brazilian tree, yields 
the red dye Brazil-wood ; that from Hmmatoxylon 
CampeacManum, a small tree of Central America, is 
the well-known and valuable dark-red dye Logwood. 

Many timber trees are of great value — e.g., the 
Mora Tree of Guiana {Dimorphandra Mora), whose 
heavy durable timber is in great repute in the British 
navy yards ; the West India Locust {HymeiuEa Gour^ T^^v^^^^^^'^Cross- 
laril), used in ship-building; the Honey Locust of the section of the ?eed 
Eastern United States {Gleditsclda triacantlios), which ghowing^lhe abim- 
furnishes a valuable timber used by wheelwrights dant endosperm.— 
for making hubs ; the Kentucky Coffee Tree of the ^^"'"^e^- 
Eastern United States {Gymnocladus Canadensis), whose red wood 
somewhat resembles Mahogany ; the Judas Trees {Cercis, sp.), whose 
wood is prized in Europe for cabinet-making. 

Sub-Order III, Mimosece, — Flowers actinomorphic, small, 
and generally collected into close heads or spikes ; stamens distinct, 
two to many times the number of petals. 

One of the most important of the vegetable gums — Gum Arabic or 
Gum Acacia — is furnished by trees of this sub-order belonging to the 
genus Acacia. The greatest supply is obtained from A. vera, and A. 
Arabica, natives of Northern Africa, Aral)ia, and the East Indies. 

The genus Acacia is abundantly represented in Australia, where 
many of its species, called Wattles, yield most excellent timber. That 
of,^. melanoxylon "is most valuable for furniture, railway carriages, 
boat-bnilding, casks, billiard-tables, piano-fortes (for sounding-boards 
and actions), and numerous other purposes. The fine-grained wood is 
cut into veneers. It takes a fine polish, and is considered equal to the 
best walnut." {Mueller.) 




I 



534 



BOTANY. 



Lysiloma Sabicu, a large Cuban tree, yields a Lard and very durable 
timber, highly valued for ship-building and for other purposes. 

Many species of Acacia and 3Iimosa are in cultivation in gardens and 
conservatories. 

Mimosa pudica, from South America, is interesting on account of its 
extreme sensitiveness to a touch or jar. On this account it is commonly 
known as the Sensitive Plant. Its leaves expand in the light and con- 
tract in darkness, and in the proper temperature close at once upon 




Fig. 488. 

Fig. 488.— Expanded compound leaf of Mimosa pudica. 
Fig 489.— Closed leaf of the same. 



Fig. 489. 



being touched or jarred, opening again, hovrever, in a few minutes 
(Figs. 488-9). 

Order Connaraceae. — Trees and shrubs of the tropics, one of which, 
Connarus Lambertii of Guiana, furnishes the beautiful Zebra- wood. 

595.— Cohort XXVII. Sapindales. Shrubs and trees, 
with usually compound leaves. Flowers often zygomorphic 
and diclinous ; ovary superior ; seeds usually without endo- 
sperm. 

Order Moringeee. — Contains three Old World trees, of doubtful 
affinity. 

Order Coriariese. — Shrubs of one genus and three to five species, 
found in the Mediterranean region, the Himalayas, Japan, New Ze'a- 
land, and South America. Their affinities are very obscure. 

Order Anacardiaceae. — The Cashew Family. Trees and shrubs, 
with gummy or milky-resinous juice, often poisonous ; fruit usually a 
drupe. Species about 450, chiefly found in the tropics. The common 






jSAPIJSrDALES. 535 

representatives of tliis order in this country are species of Rhus, of 
which B. typhina and B. glabra, Sumach, are highly ornamental, as 
well as useful, their young shoots and leaves containing much tannin 
and being much used in tanning. 

Rhus Toxicodendron, the Poison Ivy, and R. venenata, the Poison 
Sumach, both of the Eastern United States, and R. diversildba, the 
"Poison Oak" of California, are very poisonous, causing in many per- 
sons a severe cutaneous eruption. 

Mangifera Indica, of India, hut now grown in most warm climates, 
produces the excellent fruit known as the Mango. 

The Cashew Nut is the product of a large West Indian tree, Anacar- 
dium occideniale, and the Pistachia Nut of a tree of Western Asia, 
Pistacia ve?'a. 

Mastic, a resinous material used in fine varnishes, is obtained by 
making incisions into the stem of Pistacia Lentiscus, a small tree of 
the Mediterranean region. Japan Lacquer, so much used by the 
Japanese in the manufacture of many wares, is obtained in a similar 
way, from Rhus mrnicifera, and probably other species. Japanese 
Wax is derived from the waxy-coated seeds of R. succedaneum, a tree 
of China and Japan. 

Schinus molle, a Peruvian shrub, is much grown for ornament in the 
gardens of California and Italy, 

Order Sabiacese. — Trees and shrubs, mostly of the tropics. 

Order Sapindacese. — Trees and shrubs (rarely herbs), mostly with 
compound or lobed leaves. Species from 600 to 700, widely distributed. 
This order includes five well-marked sub-orders, as follows: 

Sub-Order I, Staphylece, with actinomorphic fiowers, and 
seeds with endosperm. Represented in the Eastern United States by 
the native ornamental shrul), the Bladder Nut {Staphylea trifolia). 

Sub-Order II, Melianfhece, with zygomorphic fiowers, and 
seeds with endosperm. Old World trees and shrubs. 

Sub- Order III, DodoneeWf with actinomorphic flowers, and 
seeds without endosperm ; leaves alternate. 

Ptceroxylon utile, the Sneezewood Tree of the Cape of Good Hope, 
furnishes a hard and durable timber, as also a New Zealand tree, 
Alectryon excelsum. 

Sub- Order IV, Acerinece, with actinomorphic flowers, and 
seeds without endosperm ; leaves opposite. (Figs. 490-2.) 

The genus Acer, the Maples, contains nearly all the species. 

A. campestre, the Common Maple of Europe, A. Pseudo Platanus, 
the Sycamore Maple of Europe and Western Asia, and A. platanoides, 
the Norway Maple of Europe, are valuable timber trees, occasionally 
planted here as ornaments. 

A. saccharinum, the Sugar Maple, A. rubrnm, the Red Maple, and 



536 



BOTANY. 



A. dasycarpum, the Silver Maple, all of the Eastern United States 
furnish timber much used in the manufacture of furniture. 

From the sweet sap of the first much sugar is made in the Northern 
United States. Its wood also is harder, and is known as Hard Maple,, 
to distinguish it from Soft Maple, derived from the other species. 

A. macrophyllum, the Large Leaved Maple, and A. circiaatum, the 



Figs. 490-2.— Illustrations of Acer Pseudo-Platanus. 




Pig. 490.— Section of flower. 
Fig. 492.— Kipe fruit. 



Magnified. 



Fig. 491.— Flower diagram. 



Vine Maple, both of California and Oregon, yield a hard and close- 
grained timber. 

Negundo aceroides, .the Box Elder of the Eastern United States, is a 
fine ornamental tree. N. Californicumy of the Pacific Coast, is much 
like the preceding. 

Sub-Order V. Sapindece, — Flowers actinomorphic or zygomor- 
phic ; seeds without endosperm ; leaves mostly alternate. (Fig. 493.) 



GELASTRALES. 



537 



I 



u^seulus glabra, tlie Oliio Buckeye, and several other species, are 
native ornamental trees of the sub-order, 

^. Hippocastanum, tlie Horse-Cliestnut of the Old World, is com- 
monly planted. 

Kalreuteria payiiculata, & ChmQse ixee, and Cardiospermum Halica- 
cabum, the Balloon Vine of the Southern United States, are cultivated 
as ornaments. 

Nepiheliiim LiicJii, a small Chinese tree, produces the pulpy edible 
fruits imported under the name of Litchi. N. Longan produces the 
similar fruit called Lcmgan. 

Melicocca hijuga, a tree of Guiana, yields a hard and heavy timber, 
and from Ciipania pendula, of Australia, is obtained Tulip Wood, 
which, in some respects, resembles Mahogany. 

The stem of the climbing' plant, Paullinia curassamca, of Venezuela, 
is made into the walking-sticks called * ' Supple © 

Jacks." 

596. — Cohort XXVIII. Celastrales. 

Mowers actinomorphic and monoclinous; 
oyary superior entire ; seeds usually with 
endosperm. 

Order Ampelideae. — Mostly climbing 
shrubs, with nodose stems, bearing petioled al- 
ternate leaves ; tendrils and flower clusters op- 
posite to the leaves. About 250 species are 
known ; they abound in the tropics and are 
much rarer in temperate climates. 

Vitis is tlie principal genus; it contains all 
the true Vines (grape producing), and many 
others whose fruits are inedible. (Figs. 494-501.) 

Vitis vinifera, the Vine of the Old World, has been under cultiva- 
tion from time immemorial. It is indigenous to Southern Asia, from 
whence it has been carried to nearly all parts of the woi Id. Its varie- 
ties are almost innumerable. From those grown in Soathern Europe 
wines and raisins are made, the latter being merely the sun-dried 
grapes. 

In the United States the Old World Vine is grown in the Southern 
and Pacific Coast States, and in the latter region fine raisins are made. 
In other portions of this country only the native species are grown, viz.: 

V. Lahrusca, the Northern Fox Grape ; from this have originated 
most of the common varieties, as Catawba, Concord, Isabella, etc. 

V. CBstivalis, the Summer Grape, from which we have obtained the 
Virginia Seedling, Herbemont, etc. 

V. riparia, the River-bank Grape, which has produced the Taylor 
Bullit, Delaware, and Clinton. 




Fig. 493.— Diagram of 
the flower of JEscuIus ; 
the normal circle of sta- 
mens shaded black ; of 
the interposed ones but 
two are fully developed, 
shaded lighter, the abor- 
tive ones represented by 
dots.— After Sachs. 



538 



BOTANY. 



V. vulpina, the Soutliern Fox Grape, wliicli has given rise to the 
Scuppernong and other varieties.* 

From these American grapes excellent wines are now made ; but no 
raisins have yet been made from them. 

The Virginia Cxee^QV, Ampelopsis qui nguefolia {or Vitis quinquefoUa), 

Figs. 494-501.— Illustrations of Vitis vinifkra. 




Fig. 498 



Fig. 499. Fig. 500. Fig. 501» 



Fig. 494.— Flower bud. Magnified. 

Fig. 495.— Section of flower-bud. Magnified. 

Fig. 496.— Flower without corolla. Magnified. 

Fig. 497.— Flower diagram. Fig. 498 —Fruit. 

Fig. 499.— Seed. Magnified. Fig. 500.— Cross-section of seed. Magnified. 

Fig. 501.— Vertical section of seed. Magnified. 

is o-ne of our finest native ornamental climbers, 

Javan and Sumatran species of Vitis, formerly referred to Cissus, are 
common in conservatories. 

Order Rhainnaceae. — Trees and shrubs, often spinescent, bearing 
simple, usually alternate leaves ; flowers with valvate calyx lobes. 
Species 430. Inhabitants for the most part of warm and temperate 
regions. Many possess a purgative principle. 



* This distribution of the cultivated varieties is that made by Dr 
George Engelman. American Naturalist, 1872, p. 539. 



OLACALES. 539 

The fruits of some species of Rhamnus yield yellow or green dyes, 
which are of considerable importance. 

The wood of R.frangida, of Europe, is used for making the best 
charcoal for the finest gunpowder. 

Species of Zizyphus in Africa and India produce edible fruits, one of 
which is the Jujube. 

Rhamnus cntharticus, the Buckthorn of Europe, is planted in this 
country for hedges. 

Order Stackhousiese. — Small herbs, mostly confined to Australia. 

Order Celastraceee. — Small trees and shrubs, ofien climbing, bear- 
ing simple, usually alternate leaves ; flowers with imbricate calyx 
lobes. Species about 400, natives of temperate and tiopical regions. 

Celastrus scandens, the Climbing Bittersweet of tlie Eastern United 
States, is ornamental, and is planted in this country and Europe, 

Euonymus atropurpureus, the Waahoo, or Burning Bush of the 
Eastern United States, is also found in gardens. 

The wood of E. EaropcEUS of Europe is compact and capable of 
being split into very fine pieces, and is used by watch-makers under 
the name of Dogwood. It is also used for skewers, shoe-pegs, etc. 

From the leaves of Catlia edulis, an East African shrub, a decoction is 
made which produces an agreeable excitement. The leaves themselves 
are sometimes chewed. 

597.— Cohort XXIX. Olacales. Flowers actinomorphic ; 
ovary superior, entire, one- to many-celled; seeds with copious 
endosperm. 

Order Cyrillacese. — Trees and shrubs, numbering eight species, 
represented in the Southern United States by Cyrilla racemifloy^a, the 
Ironwood, and Gliftonia ligustrina, the Buckwheat Tree, the latter a 
handsome evergreen tree, three to six metres high (10 to 20 feet). 

Order Ilicinese. — The Holly Family. Trees and shrubs with mostly 
evergreen leaves, and three- to many-celled ovary. Species 150, of 
tropical and temperate climates. 

Ilex Aquifolium, the Holly Tree of Europe, yields a white close- 
grained wood much esteemed by turners and cabinet-makers. It is 
sometimes blackened so as to resemble ebony. The tree, being orna- 
mental, is extensively planted. The bright red berries remain during 
the winter, and with the evergreen foliage are used for Christmas 
decorations. 

I. opaca, the American Holly, of the Southern States and the Atlan- 
tic coast from Massachusetts southward, resembles the preceding and 
is used for the same purposes. This and other native species are culti- 
vated in gardens. 

The leaves of I. Paraguayensis, a small South American tree, furnish 



540 BOTANY, 

the Paraguay tea, sometimes called Mate. It contains Caffeine, the 
active principle in tea and coflfee. 

Order Olacinese. — Trees and shrubs, about 170 species, almost en- 
tirely of the tropics, 

598.— Cohort XXX. Geraniales. Flowers often zygo- 
morphic ; ovary superior, entire, lobed, or sub-apocarpous. 
Order Chailletiaeese. — Tropical shrubs and trees. 

Order Meliaceae. — Trees (rarely undershrub8),with mostly piunatelj 
compound leaves ; stamens united into a tube ; ovary entire. Species, 
270, nearly confined to the tropics. 

Several trees yield valuable timber. 

Melia Azedarach, the Pride of India Tree, indigenous throughout 
Western Asia, now naturalized in all the Mediterranean region, and 
the Southern United States, is a fine tree, whose reddish wood is sus- 
ceptible of a beautiful finish. 

Swietenia MaJiogoni, a native of tropical America (barely reaching 
South Florida), yields the well-known Mahogany wood. The trees 
are of great thickness, sometimes being as much as two metres in 
diameter. 

Cedrella odorata, of Jamaica, yields Jamaica Cedar. 

C. Toona, of India, produces Chittagong wood. 

C, australis, an immense Australian species, resembles the Jamaica 
Cedar. The wood of the three foregoing species of Cedrella is fine 
grained, and well adapted to many uses. 

Ghloroxylon Swietenia, of Ceylon and Western India, is a large tree, 
whose fine-grained satin-like wood, called Satin Wood, is much prized 
in cabinet and furniture making and fine turnery. 

Order Burseraceae, — Trees and shrubs, abounding in resinous or 
oily secretions ; species, 145, nearly all tropical. 

Balsamodendron Myrrha and B. Kataf, small Arabian trees, yield 
Myrrh. 

B. Africanum, of Eastern Africa, produces African Bdellium. 

Olibanum, an incense resin, is obtained from Bosioellia thurifera, a 
lofty tree of Central India. 

Bursera gummifera. West Indian Birch, of South Florida and the 
West Indies, yields a gum resin called Chibou or Cachibou. 

Order Ochnaceae, — Tropical shrubs and trees with a watery juice. 

Order Simarubaceae. — Shrubs and trees, with scentless foliage ; 
leaves generally compound and alternate ; stamens distinct. About 
112 species, almost confined to the tropics, are known. The bitter bark 
and wood of many species are made use of in medicine. That from 
Quassia amara, a small tree of tropical America, is the Quassia of 
pharmacy. From a West Indian tree, Simaruha amara, the drug 
Simaruba Bark is obtained. 



OEBANIALES. 



541 



Ailanthus glandulosus, the Tree of Heaven, a native of China, is com- 
monly planted in the United States as a shade tree. Its wood is valu- 
able in cabinet-making. 

Order Rutaceae. — Tiie Rue Family. Shrubs and trees, rarely herbs, 
witli glandular-punctate heavy-scented foliage ; leaves generally com- 
pound and alternate ; stamens generally distinct. The order as here 
considered includes 650 known species, widely distributed in tropical 

Figs. 502-505.— Illustkations or Citrus Aur^ntium. 





Fig. 503. 




Fig. 505. 

Fig. 502.— Section of flower. Magnified. 
Fig. 503.— Part of androecium. Magnified. 
Fig. 504.— Flower diagram. 
Fig. 505.— Calyx and ovary. Magnified. 

and temperate climates. Seven tribes, most of which were formerly 
considered to be orders, are recognized by Bentham and Hooker. 

Tribe Aurantiece, with actinomorphic, monoclinous flowers, 
baccate (berry-like) fruits, and seeds without endosperm. (Figs. 502-5.) 

Citrus Aurant'Um, the Sweet Orange, is an Indian tree, now grown 
throughout all warm countries of the world for its well-known fruits. 

C. Limonum, the Lemon, is a native of Northern India, now widely 
distributed. It was introduced into Europe during the Crusades. 

Other species of Citrus yield valuable fruits, as C. medica, the Citron ; 
C. Limetta, the Lime ; C. decumana, the Shaddock ; C. Bigaradia, the 
Seville or Bitter Orange, etc., etc. 

The hard yellow wood of the Orange is valued for inlaying 



542 BOTANY. 

Tribe Toddnllece^ witli actinomorpliic, mostly diclinous flowers, 
coriaceous or baccate fruits, and seeds witli endosperm. 

Ptelea trifoliata, the Hop Tree, of the Eastern United States, 8kirro- 
mia Japonica, a small Japanese shrub, and two species of Phelloden- 
dron, from Manchuria, are planted in gardens. 

Tribe Xanthoocylem^ with actinomorpliic, mostly diclinous 
flowers, usually capsular fruits, and seeds mostly with endosperm. 

Xanthoxylum Americanum, the Common Prickly Ash, of the 
Northern United States, and X. Clava-Herculis, the Southern Prickly 
Ash, of the Southern States, are ornamental shrubs, and are often 
planted. 

Tribe Soronieoe, — Australian shrubs. 

Tribe Diosmecef with actinomorpliic, monoclinous flowers, cap- 
sular fruits, and seeds without endosperm. 

Species of Diosma and Barosma, pretty African shrubs, are to be found 
in conservatories. From their leaves the drug 
Buchu is obtained. 

Tribe HuteWf with generally actinomorphic, 
monoclinous flowers, capsular fruits, and seeds 
with endosperm. (Fig. 506.) 

Buta graveolens, the Common Rue of the gar- 
dens, is a native of Southern Europe and West- 
ern Asia. 

.„. ^^„ ^. ^ Dictamnus Fraxinella, Fraxinella, or the Gas 

Fig. 506.— Diagram of „, , . , ' , , 

the flower of Dictamnus Plant, is a heavy-scented ornamental plant, 

Fraxivdla, the hiterpos- ^^ glandular folia^re secretes a volatile oil, 

ed stamens (oi later on- =" '^ ' 

gin) slightly shaded.— Af- which is said sometimes to flash into flame 

ter Sachs. ^^^^ ^ ^iglit is brought near to it. (Figs. 116-7.) 

Tribe Cusj^nrieWf with zygomorphic, monoclinous flowers, cap- 
sular fruits, and seeds without endosperm. 

Oalipea cusparia, a large tree of Guiana and Brazil, furnishes a bit- 
ter medicinal bark, known as Angustura Bark. 

Order Geraniacese. — The Geranium Family. Mostly herbs (rarely 
shrubby or arborescent) ; leaves opposite or alternate, simple or com- 
pound ; stamens more or less united below ; species, 750, mostly of 
temperate and sub-tropical climates. 

Many are cultivated as ornaments. 

Impatiens Bahamina, the Garden Balsam, or Touch-Me-Not, some- 
times erroneously called "Lady's Slipper," is a well-known annual 
from India, which has been cultivated for more than two hundred and 
fifty years. The name Touch-Me-Not (referring to its elasrically open- 
ing fruits) is shared by two pretty native species. (Fig. 507.) ■ 

Oxalis contains several native species of Wood Sorrel, all of which 




OEBANFALES. 



543 



are pretty, and many exotic species (mostly South African), wliicli are 
in common cultivation. 

TropcBolum majus, the Nasturtium, from South America, is in com- 
mon cultivation. The edible tuberous roots of 2\ tuberosum, of Peru, 
are used instead of potatoes in some parts of South America. 

Pelargonium is another South African genus, which has furnished 
us vrith many fine greenhouse and garden flowering plants, most of 
which are erroneously called Geraniums, 

The true Geraniums belong to the genus of that name represented in 
this country by eight or nine wild species. 

Erodium cicutarium, the Alfilaria, of California, " is a valuable and 
nutritious fbraire plant reputed to impart an excellent flavor to milk 
and butter." {Brewer.) 

Order Zygophyll- 
aceee, — Shrubs and herbs 
(a few trees), with oppo- 
site compound leaves ; 
stamens distinct ; spe- 
cies, about 100, almost 
confined to the tropics, 

Ouaiacum officinale, 
the Lignum-vitse, of the 
West Indies, is a tree 
six to nine metres (20 to 
30 feet) high, whose dark 
red, almost black, heart- 
wood is exceedingly 
hard ; it furnishes the 
best material for ship's 
blocks, pulleys, etc. 

Larrea Mexicana, the 
Creosote Bush of Arizona, is a curious diffusely branched evergreen 
shrub, with a very strong creosote-like odor. 

Order Malpighiacese, — Trees and shrubs, often climbing ; natives 
for the most part of the tropics ; species, 580, some of which are culti- 
vated in greenhouses. 

Order Humiriaceae. — Balsamic trees and shrubs of tropical America 
and Africa. 

Order Linacese. — The Flax Family. Herbs, shrubs, and a few trees, 
with alternate or opposite simple leaves ; stamens more or less united 
below ; species, 135, widely distributed in temperate and tropical 
climates. 

The most important plant of the order, and one of the most impor- 
tant in the vegetable kingdom, is the Flax, Linum usitatissimum, cul- 
tivated from time immemorial for its fibres, called linen (the bast fib'es 





Fig. 50T. — A, the fruit of Impatiens BaUamina. B, 
the same after dehiscence ; a, a, carpels ; gr, seeds. 
— After Duchartre, 



544 



BOTANY. 



of the cortical part of tlie stem). The mummy cloth of ancient Egypt 
IS composed of flux fibres, and in the remains of the "lake dwellings" 
in Switzerland, fragments of linen cloth have been found. The yjlant 
appears lo be indigenous in the south of Europe, as well as in the 
regions eastward in Asia ; it is now cultivated throughout the North 
and South Temperate Zones. The seeds are rich in oil, which is 
extracted by pressure, producing the Linseed-oil of commerce ; the 

Figs. 508-10. — Illustrations op Linum usitatissimum. 





Fig 509. 




Fig. 508. 

Fig. 508.— Inflorescence. 
Fig. 510.— Diagram of flower. 



Fig. 510. 
Fig. 509. — Section of flower. Magnified. 



compressed refuse is called oil-cake, and is much used as food for 
cattle. (Figs. 508-10.) 

Erythroxylori Coca, a South American shrub, is cultivated in 
Bolivia and New Granada for its stimulating leaves, which are cheweci 
like tobacco. 

599.— Cohort XXXI. Malvales. Flowers usually actino- 
morphic ; stamens indefinite, generally monad elplious ; ovary 



MAL VALES. 



545 



Figs. 511-513.- 



-iLLtrSTRATIONS Off ThEOBRO- 

MA Cacao. 



superior, generally tkree- to many- celled ; seeds mostly with 
endosperm. 

Order Tiliacea^. — Tlie Linden Family. Trees and slirubs (a few 
herbs), witli mostly alternate simple leaves ; stamens distinct, or some- 
what united below. Species 
330, mostly tropical. 

Tilia Europma, the Lime 
or Linden Tree of Europe 
and Siberia, is a large and 
valuable tree, yielding a soft 
white wood much esteemed 
by carvers, musical instru- 
ment makers, and others. 
The fibre of its bark is used 
for making coarse mats, and 
its flowers produce a great 
quantity of most excellent 
honey. 

T. Americana, the Amer- 
ican Linden, Linn, or Bass- 
wood of the Eastern United 
States, resembles the preced- 
ing, and is equally valuable. 

While the wood of our rep- 
resentatives of the order is 
soft, that of some tropical 
species is very hard — e.g., 
Sloanea dentata, a West In- 
dian tree, which has received 
the significant name of 
Break-Ax Tree. 

Corchorus capsularis, a tall- 
growing annual of India, 
yields the Jute fibre now ex- 
tensively used in making 
gunny bags, coarse carpets, 
and even fabrics of consider- 
able fineness. 

Order Sterculiacese. — 
Trees and shrubs (a few 
herbs) with alternate simple 

or compound leaves ; stamens more or less united into a tube. 
520 species contained in this order are almost entirely tropical. 

Theohroma Cacao, the Chocolate Tree of tropical America, attains a 
height of five to six metres (16 to 20 ft.), and bears elongated ribbed 




Fig. B.13. 



Fig. 511. 

Fii?. 511.— Frnit 0^ natural size). 

Fi<j. 512.— Seed. iMa^ified. 

Fig. 513.— Seed cut vertically. Magnified. 



The 



546 



BOTANY. 



fleshy fruits, each containing fifty or more oily seeds (Figs. 511-13). 
The seeds are roasted and then ground, and made into a paste and dried, 
constituting the Chocolate or Cocoa of commerce, according as vanilla, 
sugar, and other substances are, or are not added. Chocolate and Co- 
coa contain Theobromine (C7 Hg N4 O2), an alkaloid similar to Caffeine. 
Order Malvaceae. — The Mallow Family. Herbs, sluubs, and trees, 
with alternate simple leaves ; stamens indefinite, united into a tube ; 

Figs, 514-19.— IixLustkations or Malvace^ {Malva sylvestris). 



/V/^ 




Fie. 519. 



Fig. 517. 



Fig. 518. 



Fig. 514.— Section of flower. Magnified. Fig. 515.— Androeciuin. Magnified. 
Fig. 516.— Stamen. Magnified. Fig. 517.— Calyx and pistil. Magnified. 

Fig. 518.— Flower diagram. Fig. 519.— Fruit. 



anthers one-celled. Species about 700, widely distributed, but most 
abundant in tropical regions. (Figs. 514-19.) 

Gossypium herbaceum, the common Cotton Plant of tropical and sub- 
tropical countries, was probably derived originally from some part of 
India. Its culture by the East Indians and Egyptians was known 
many centuries before the Christian era. In England the manufacture 
and use of cotton cloth began during the latter part of the sixteenth 



G UTTIFERALES. 



54:7 



century. The culture of cotton in North America dates from almost 
the first settlements in the Southern States, and the cotton crop is now 
more valuable thau the product of any other single cultivated plant iu 
the United States. It is extensively cultivated in the West Indies, 
Brazil, Egypt, and India. 

The fibre of cotton consists of greatly elongated hairs (trichomes), 
which develop in great numbers upon the outer surface of the seed- 
coats ; these are at first cylindrical, but upon drying, as the seed-pod 
approaches maturity, they collapse and appear flat and more or less 
bent and twisted. 

Some East and West Indian trees of the genus Bomhax produce an 
abundance of a similar fibre, which is fine and silky, hence the trees 
are known as Silk Trees. It is said, however, that the fibre cannot be 
woven, and it is at present only used fur stuffing cushions, etc. 

The bast fibres of the stems of some species are useful. Species of 
8ida in India, China, and Australia, of Plagianthus in New Zealand, 
and of Thespesia and Hibiscus in tropical 
America, are thus used ; from the last the 
fibre called Cuba Bast is obtained. 

Hibiscus esculentus, the Okra or Gumbo 
of tropical America, produces mucilaginous 
edible pods, which are much used in the 
Southern United States. 

Species of Durio in the Malay Archipel- 
ago, and of Matisia in New Granada, fur- 
nish the inhabitants of those countries with 
valuable fruits. The wood of most of the 
species of the order is very soft and com- 
pressible ; this is particularly the case with 
a West Indian tree, Ochroma Lago-pun, whose wood, known as Cork 
Wood, has been used as a substitute for cork. 

The Baobab Tree of tropical Africa is remarkable for the enormous 
size of its rounded spreading top and the thickness of its short stem. 

Among the more common ornamental plants of the order are Mallows 
{Malva), Rose Mallow {Hibiscus), Hollyhock (Althcea), Gallirhoe, etc. 

600.— Cohort XXXII. Guttiferales. Flowers actino- 
morpliic ; stamens indefinite ; ovary superior, three- to many- 
celled. 

Order Chlsenaceee. — A few shrubs and trees of Madagascar. 

Order Dipterocarpeae. — Tropical trees (rarely shrubs), about 112 in 
number, the most important of which is Dryobnlanops Camphora, the 
Kapor or Camphor Tree of Borneo and Sumatra, which attains a height 
of forty metres (130 ft,), and yields a hard red timber used in boat- 
building. Its resin is called Sumatra Camphor, and is much used in 
China and Japan. 




Fi?. 520.— Flower diagram 
of Gordonia Lasianthus. 



148 



BOTANY. 



Figs. 521-5.— Illustrations of Camel- 
lia Chineksis. 



Order Ternstrcemiacese. — Trees and shrubs with alternate (rarely 

opposite) leaves, and mostly nionoclinous axillary or racemed flowers. 

Species 260, mostly tropical. (Figs. 520 and 521-5.) 

Several ornamental species are indigenous to the Southern United 

States — e.g., the Loblolly Bay {Gordonia Lasianthus, Fig 520), a tree 

nine to fifteen metres (30 to 50 ft.) high ; G. puhesceus, the Mountain 

Bay ; and two shrubby species of Stiiaj'tia. 

The most common exotic species cultivated for ornament is the 

Camellia {Camellia Japonica) a well-known hot-house shrub from 

China and Japan. 

The Tea Tree {Camellia CJiinensis or Thea Chinensis) is an evergreen 

tree three to five metres high, and 
a native, probably, of Southern 
and Eastern Asia. It has been 
cultivated for ages by the Chi- 
nese, and has lately been intro- 
duced to a limited extent into 
other countries. In preparing the 
leaves they are carefully picked, 
and then are subjected to alternate 
drying, pressing, rolling and air- 
ing until the proper chemical 
changes have taken place, and a 
sufficient part of the water is 
driven off. The different kinds 
and qualities of tea depend upon 
the rapidity of the process, and 
also upon the age of the leaves 
used, the more rapid process and 
the younger leaves producing the 
finer green teas, the slower pro- 
cess and older leaves producing 
the Mack teas. Somewhat appears 
also to depend upon the variety of 
the plant, there being, it is gene- 
rally admitted, two varieties or 

races, viz., var. mridis and var. BoJiea. 

Tea leaves after preparation contain the alkaloid Caffeine (Cg Hio 

N4 O2 + H2 0), which also occurs in roasted coffee. 

Order Guttifereae.— Trees and shrubs with yellowish or greenish 

resinous juice, opposite leaves, and mostly diclinous flowers. Species 

230, all tropical. 

Garcinia Morella, a small tree of Siam, produces Gamboge, a valuable 

color used in painting. Incisions are made into the bark, and the juice 

which exudes is gathered and dried, constituting the crude Gamboge. 
The Mano-osteen, a fruit about as large as an apple, and considered 




Fig. 523. 



Fig. 525. 



Fig. 521.— Ripe fruit. Magnified. 
Fig. 522.— Seed. Magnified. 
Fig. 523.— Section of seed Magnified. 
Fig. 524.— Embryo. Magnified. 
Fig. 525.— Half embryo, innci face. Mag 
nified. 




CABTOPHYLLALES. 549 

to be one of the most delicious of all fruits, is produced by Garcinia 
Mangostana, a small tree of tlie Moluccas. 

The fruit of Mammea Americana, a tall West Indian tree, is known 
as the Mammee Apple. It is as large as a melon, and its yellow pulp 
is said to be delicious. 

A Central American species of Calophyllum yields a pale reddish, very 
durable timber known as Santa Maria wood. 

Order Hypericacese. — Herbs and shrubs (a few trees) with opposite 
glandular-punctate leaves, and monocliaous flowers. Stamens united 
into three or five bundles (Fig. 526). Species 210, ^ 

mostly found in temperate climates. 

Our species are all herbs or low shrubs, be- 
longing to the genera Hypericum and Ascyrum. 

A species of Cratoxylon, in tropical India, is a 
large tree with dark brown wood. 

Order Elatinacese. — Containing a few marsh 
plants. 

601.— Cohort XXXIII. Caryophyll- Fig. 526.-Diagram of 

, -r^T . • , . "^ .-^ •^ the flower of Eyperi- 

ales. -b lowers actmomorpnic ; stamens cum eaiycinum.— After 
generally definite, usually as many or 
twice as many as the petals ; oyary superior, one-celled ; pla- 
centa usually central and free ; seeds with endosperm. 

Order Tainariscii><^ae. — Mostly shrubs of the Old World, with mi- 
nute alternate simple heaves. 

Of the forty species, but three are found in the New World, and all 
these reach our extreme Southwestern border. 

Tamarix Gallica, the Tamarisk of Europe to India, is a common 
ornamental shrub in this country. 

Order Portulacacese. — Herbs and a few small shrubs, with alter- 
nate or opposite leaves ; sepals generally two. Species 125, widely dis- 
tributed, but most abundant in the New World. 

Portulaca oleracea, the common Purslane, is an East Indian, or possi- 
bly South European weed. It was formerly used as a pot herb. 

P. grandiflora, the Portulaca of the gardens, is a pretty flowering 
annual. 

Claytonia and Calandrinia, yvlnch have many native representatives, 
are ornamental. 

Order Caryophyllaceae. — The Pink Family. Mostly herbs with 
opposite leaves ; sepals four or five, free or united into a tube ; placenta 
central. Species 800, distributed throughout the world, but most 
abundant in Arctic, Alpine, European, and Western Asiatic coun- 
tries. 



550 



BOTANY, 



Aside from the ornamental species and the weeds, the order posBesses 
no plants of much economic importance. 

The roots of Saponaria ojficinalis contain Saponin, and are detergent, 
but not sufficiently so to be much used. 

Among the ornamental plants are the Carnations and Clove Pinks 
{Dianthus sp.), the Mullein Pink (Lychnis), Catchfly {Silene), Bouncing 
Bet {Saponaria), GypsopJdla, etc. 

Among the weeds are species of Cerastium (Fig. 527), Spergula, and 

the Corn Cockle, 
Lychnis Githago. 
The latter is often 
quite abundant in 
wheat fields, to the 
great detriment of 
the flour manufac- 
tured from the 
wheat. 

Order Franken- 
iaceae. — Mari- 
time herbs and 
low shrubs resem- 
bling Caryophyll- 
aceae, but with par- 
ietal placentae. 

602. — Cohort 
XXXIV. Poly- 
galales. Flow- 
ers actinomorph- 
ic or zygomorpli- 
ic ; stamens defi- 
nite, as many 
as or twice as 

Pig. 527.— Tufloreecence of Cerastium collinum. t^ pri- -mg-r,^ ^^ f>,o ■y\(^\ 
mary axis ; V^ secondary axes ; t", tertiary axes ; V", qua- -1^^^^^ J <^^ ^^^^ V^ ^~ 
ternary axes ; t"", quinary axes.— After Duchartre. ojg . oyarV Usual- 

ly two-celled ; seeds mostly with endosperm. 

Order Vocliysiacese. — Trees with a resinous juice, and opposite or 
verticillate leaves ; flowers zygomorphic. Species about 100, confined 
to tropical America. 

Vochysia Ouianensis, of Guiana, furnishes the Copai-ye Wood, there 
used for making boat-oars, the staves for sugar hogsheads, etc. 

Order Polygalaceae. — Mostly herbs with alternate leaves ; flowers 
zygomorphic. Species 400, distributed throughout temperate and 
tropical countries. 




PARIETALES. 551 

A bitter principle, whicli is sometimes emetic and purgative, per- 
vades the order. 

Some South African species of Polygala are grown as ornamental 
plants in conservatories. A few have a little reputation as medicines. 

Order Tremandrese, containing a few Australian shrublets. 

Order Pittosporaceae. — Trees and shrubs with alternate leaves, 
and actinomorphic flowers ; petals cohering into a tube. Species 
ninety, of Africa, India, China, and Australia. 

Pittosporum Tobira is a common plant in conservatories. 

P. undulatum, of Australia, attains a height of twenty to twenty-five 
metres (70 to 80 ft.), and its wood resembles Boxwood. 

Climbing species of Sollya and other genera are grown in green- 
houses. 

603.— Cohort XXXV. Parietales. Flowers actinomorph- 
ic or zygomorphic ; stamens definite or indefinite ; ovary 
usually one-celled, with parietal placentae. 

Order Bixinese. — Trees and shrubs with alternate simple leaves, 
actinomorphic flowers, and generally indefinite stamens ; seeds with 
endosperm. Species 160, mostly tropical. 

One or two species of Amoreuxia barely reach our extreme South- 
western border. 

Bixia Orellana, a small South American tree now cultivated in many 
tropical countries, produces fruits whose orange-red pulp when pre- 
pared and dried is the valuable dye known as Arnotto. 

The fruits of some species are eaten, and a few gums are derived 
from others. 

Order Canellacese, containing four or five species of tropical trees. 

Ganella alba yields Canella Bark, which is used in medicine. 

Order Violacese. — The Violet Family. Herbs and shrubs with 
mostly alternate leaves, zygomorphic flowers, and definite stamens ; 
seeds with endosperm. Species 240, widely distributed in temperate 
and tropical regions. 

An emetic and laxative principle is common in the plants of this 
order. 

The genus Viola, the Violets, includes about half of the species of 
the order ; many of these are indigenous to parts of the United States, 
and nearly all of these, as well as the exotic species, are ornamental. 

V. odorata, the Sweet Violet, and V. tricolor, the Pansy, both natives 
of Europe, are common in gardens and door-yards. Of the latter there 
are almost numberless varieties. 

Several Brazilian shrubby plants of the order are cultivated in green- 
houses. 

The root of lonidium Ipecacuanha, a Brazilian shrub, is the White 
Ipecacuanha of pharmacy. 



I 



502 



BOTANY. 



A Peruvian tree, Leonid glycycarpa, produces edible pulpy fruits as 
large as a peach. 

Order Cistacese. — Herbs and slirubs with actinoiuorpliic flowers. 
Species about sixty, mostly of temperate climates. 

A shrubby Cistus from the South of Europe is common in green- 
houses. 

Some of our native species of Frost weed {Helianthemum) and Hud- 
ftonia are pretty. 

Order Resedacese. — Herbs (a few shrubs) with alternate leaves, 
mostly zygomorphic flowers, indefinite stamens, and seeds without 
endosperm. Species twenty to twenty-five, confined to the Mediter- 
ranean region and South Africa, with the exception of two or three spe- 



FlGS. 528-30.— IlLUSTBATIONS of CRUCIFEKJa (WAIiLFLOWER). 




Fig. 528. 



Fig. 530. 



Fig. 5-29. 



Fig. 528. 



-Flower diagram. 

Fig. 530.- 



Fig. 529.— Section of Flower. Magnified. 
-Androecium. Magnified. 



cies which reach India, one of which {Oligomeris subulata) extends to 
California. 

Reseda odorata is the well-known Mignonette, probably a native of 
the Eastern Mediterranean region. 

The foliage of R. luteola, an annual of Europe called Dyers' Weed 
or Weld, furnishes an important yellow dye. 

Order Capparidaceae. — Herbs, shrubs and trees with mostly alter- 
nate leaves, actinomorphic flowers, mostly indefinite (never tetradyna- 
mous) stamens, and seeds without endosperm. Species 300, mostly 
tropical or sub-tropical. An acrid volatile principle prevails in the 
order. 

Capparis spinosa, a stiff" prickly-branched shrub of the Mediterranean 
region, is extensively cultivated in Europe for its unopened flower 
buds, which preserved in vinegar constitute the condiment known as 
Capers. 

Cleome integrifoUa, a native of the Western Mississippi Valley, and 



PARIETALES. 



553 



<7. pungens, of Soutli America, are fine flowering plants cultivated in. 
gardens. 

Order Cruciferee. — The Crucifer Family. Herbs and a few low shrubs 
with actinomorphic flowers, tetradynamous stamens, and seeds without 
endosperm (Figs. 528-41). This large order includes 172 genera and 
about 1200 species, which are distributed throughout the temperate re- 
gions of the world, but are most abundant in Southern Europe and 
Asia Minor. The prevailing principle in the order is pungent and stim- 
ulant. 

The order is divided by Bentham and Hooker into ten tribes, distin- 
guished by the shape of the fruit and the disposition of the cotyledons 
in the seed, whether incumbent or accumbent (Figs. 536 to 541). 

The order furnishes a few food plants of some importance. 

Brassica oleracea, a wild plant of the Atlantic coast of Europe, is 

Figs. 531-5.— Illustrations of Crucifer^ (Shepherd's Purse). 





Fia. 532. 




Fig. 533. 



Fig. 534. 



Fro. 531. 



Fig. 535. 

Fig. 531.— Vertical section of flower. Magnified. 

Fig. 532.— Pistil and stamens. Magnified. 

Fig. 533.— Ripe capsule splitting open. Magnified. 

Fig. 534.— Seeds on placeiitse, the capsule-valves removed. Magnified. 

Fig. 535.— Cross-section of capsule. Magnified. 

probably the original form from which have been derived by long cul- 
tivation tlie following races, which are now almost, if not quite, entitled 
to be regarded as species, differing as they do fully as much from one 
another as many wild species : 

Race I. Cauliflower, in which the thickened and consolidated flower 
peduncles constitute the edible portion of the plant. 

Race II. Bore Cole or Kale, in which the expanded but tender leaves 
' of the tall stem are the edible parts. 

Race III. Brussels Sprouts, resembling the last, but with thick edi- 
. ble buds in the axils of the leaves. 

Race IV. Cabbage, in which the leaves do not expand, but forma sin- 
gle large thick edible bud or " head." 



554 



BOTANY. 



Race V. Kold-Rahi, in wliicli the sliort and few-leaved stem becomes 
thick, bulbous, and edible. 

B. campestris, of the same regions as the preceding, has given rise to 
the various kinds of Turnips. Colza and Rape also are probably vari. 
eties ; the latter are extensively cultivated in Europe for iheir oily 
seeds, from which useful oils are obtained by pressure. 

Rajphanus sativus, the Radish, is a native of China. 

Nasturtium Armoracia, the Horseradish of Europe, has long been 
cultivated for its pungent roots, w^hich are used as a condiment. Ac- 
cording to Dr. Gray, the plant, for some unknown reason, does not pro- 
duce seeds in this country. 

N. officinale, Water Cress of Europe, and nov7 run vt^ild in many parts 



Pigs. 536-41. — Seeds op CKUcirEKiE. 





Fig. 537. 



Fig. 540. 




Fig. 541. 



Fig. 539. 



Fig. 536.- Seed of Erysimum. Magnified. 
Fig. 537.— Lmigitudinal section of seed. Magnified. 

Fig. 538.— Cross-section of seed, showing incumbent cotyledons. Magnified. 
Fig 539. —Longitudinal section of seed oi Arabis. Magnified. 
Fig. 540. — Cross-section of $eed ofArabU, accumbent cotyledons. Magnified. 
Fig. 541.— Cross-section of seed of Barbarea, imperfectly accumbent cotyledons. 
Magnified. 

of the United States, and many other rapidly growing foreign and na- 
tive species, are used as salads. 

Brassica alba. White Mustard, and B. nigra, Black Mustard, both 
natives of Europe, are grown for their seeds, which when ground con- 
stitute the common condiment Mustard. It is also of considerable 
value in medicine. 

Isatis tinctoria, a tall-growing European bieiiniiil, was formerly ex- 
tensively grown for the blue dye obtained from it. 

The most important ornamental plants of the older are the Wall- 
flower {ClieiraMlius), Gilly Flower or Brompton Stock {Matthiola), 
Rocket (Hesperis), Candytuft (Iberis), Honesty {L'unaria), Sweet Alys> 
sum (Alyssum), etc., etc. 

Several of the species are troublesome weeds— e^., Shepherd's Purse 
{Capsella), which has come to this country from the Old World ; Pepper- 
grass (Lepidium), native and introduced ; False Flax (Camelina) from 
Europe ; Charlock and Mustard (Brassica) from Europe. 



PARIETALES. 



555 



The curious plant called the Rose of Jericho (Anastatica hierochun- 
tica), often sold as a curiosity, is a small annual, native of Arabia, 
Egypt, and Syria. The mature plant after ripening its seeds contract 
into a rounded mass, and is uprooted and blown about by the windjj 
When, however, the dry and dead plant is moistened, it expands, clos- 

FiGS. 542-5.— Illustrations of Papaver Rh(eas. 




Fig. 542. 





Fig. 543. 

Fig. 542.— Vertical section of flower. Magnified, 
Fig. 543.— Pistil and stamen. Magnified. 




Fig. 545. 

Fig. 544.— Flower diagram. 
Fig. 545.— Ripe fruit. 



Inj^ again when dry. On this account it is also called the Resurrection 
Plant. 

Order Fumariacese. — Herbs with watery juice, alternate, usually 
divided leaves ; flowers zynroinorpliic ; stamens definite, four, five or 
six and diadelphous. Species about 100, natives of warmer portions of 
the Nortli Temperate Zone and of South Africa. Tliey possess an acrid 
and astringent principle. 

Bentham and Hooker, in the " Genera Plantarum," unite this order 



556 BOTANY. 

witli tlie next, but this arrangement lias not generally been adopted by- 
botanists. 

Dicentra spectaMUs, the Bleeding Heart, a sbowy Chinese species, is 
in common cultivation for its heart-shaped pink-red flowers. Our 
native species, D. Canadensis and D. Cucullaria, are pretty, and are 
sometimes cultivated. 

Climbing Fumitory {Adlumia cirrhosa) is a delicate native cliniber, 
also cultivated in gardens. 

Order Papaveracese. — The Poppy Family. Herbs and a few low 
shrubs, with a milky or colored juice, alternate leaves, and actino- 
morphic flowers; stamens indefinite, seeds with endosperm (Figs. 542- 
5). The order as here constituted includes ^bout sixty species, natives, 
for the most part, of the North Temperate Zone. They contain a nar- 
cotic principle. 

The most important plant of the order is the Opium Poppy {Papaver 
somniferum), a native of many parts of the Old World, and now culti- 
vated in Southern Europe and India. Opium is obtained from it by 
scarifying the full-grown but still green capsules : the juice which ex 
udes soon hardens and is then collected, constituting in this state the 
crude Opium of commerce. 

Opium contains from six to twelve per cent of an alkaloid substance. 
Morphia (C17 H19 N O3 + H2 0), to which its narcotic properties are 
mainly due. 

Other species of Papaver, several of which are in common cultiva- 
tion in flower-(rardens, contain Opium, but it is not considered to be as 
valuable as that from the Opium Poppy. 

Sanguinaria Canadensis, the Blood-root, a pretty native plant of the 
Eastern United States, contains in its red juice narcotic properties sim- 
ilar to those of Opium. 

Among the ornamental plants besides Poppies and Blood-root, are 
Bocco7iia, a tall-growing Cliinese perennial, Argemone, from Mexico, 
and Eschsclioltzia, from California. 

Order Sarraceniaceas. — Perennial marsh herbs, with radical tubular 
leaves, solitary actinomorphic flowers ; stamens indefinite ; seeds with 
endosperm. Species ten, nine of which are natives of the United 
States. (Fiffs. 546-7.) 

Sarracenia purpurea, tlie common Pitcher Plant of the Northern 
and Eastern United States, inhabits peat bogs and " cranberry marshes." 
Its open, pitcher-like leaves contain water, in which many decaying in- 
sects may always be found. The structure of the interior surface of 
the pitcher is such as to make it exceedingly difl&cult for insects, when 
once in it, to escape, being lined for some ways down with myriads of 
short and sharp stiff bristles which point downwards. Without doubt 
these plants are nourished by the decaying insects in their leaves, and 
to this extent they are to be regarded as saprophytes. In some Southern 
species, as, for example, S. variolaris and S. psittacina, the pitcher is 



BANALES. 



65? 



Covered by a hood mucli as in Nepenthes (page 483), and in tliese water 
is also found (undoubtedly a secretion in tliese cases) in whicb are many 
decayinpr insects. Moreover, in these and some other species drops of a 
sweetish honey-like substance are secreted on the leaves, which appar- 
ently serve to lure insects to the marg^in of the pitcher. 

The California Pitcher Plant {DiTlingtonia Ga ifornica) of the north- 
ern part of California, has long tubular leaves which are arched over at 




Fm. 547. 
the top, so that the ori- 
fice opens downward ; 
from the orifice there 
hangs down a forked 
blade, which is more or 
less covered with a 
sweet secretion, and 
within the tube there is 
always found water 
more or less filled with 
insects. The arrange- 
ment here is evidently 
one well fitted to cap- 
ture insects, which, 
^^ after maceration, are 

^ ^ absorbed for the 

Fig. 546.— Flower and leaves of /So',rracmm;9MrpM/'(?a. ,^^„^;aiimon+ r^f iLa 
K natural size.-From Le Maout and Decnisne. nourisUment Ol lue 

Fig. 547.— Pistil cut vertically. — From Le Maout and plant. 

The third genus, 
Heliamphora, contaiiis a single species, native of Venezuela. 

604.— Cohort XXXVI. Ranales. — Plowers mostly actino- 
mori)]iic ; stamens rarely definite ; carpels free, very rarely 
connate ; seeds with copious endosperm. 

Order Nymphseaceae. — The Water Lily Family. Aquatic herbs, 
■with usually floating piiltate leaves; flowers solitary, monoclinous ; 
petals and stamens generally numerous ; carpels mostly united, rarely 
free. Species thirty-five, widely distributed. 



558 



BOTANY. 



Kelumhium luteum, tlie Yellow Water Lily, or Water Chinqnopin, 
is coiijiiion in the i)()nds and rivers of the Mississippi Valley anii lae 
Southern States. Its nut-like fruits, which are imbedded in the larjre 
top-shaped receptacle, are edible. (Figs. 548-9.) 




Fig. 548.— Leaf, flower, and fruiting receptacle of Nelumbium luteum. }4 natural 
size.— From Le Maout and Decaisne. 

iV. speciosum, the only other species of the genus, occurs in Southern 
and Southeastern Asia. 
Nymphcea odorata and N. tuberosa are the well-known White Water 
Lilies of the Eastern United States. X. ccerulea 
and iV. Lotus are common on the Nile. 

Victoria regia, the Victoria Lily of the Ama- 
zon Valley in South America, is remarkable for 
the size of its leaves and flowers ; the former are 
peltate, perfectly circular, and two metres or more 
in diameter, and the slender petioles are often 
three metres long ; the flowers resemble those of 
our White Water Lilies, and are twenty-five to 
thirty centimetres in diameter ; upon first opening 
they are pure white, but upon opening a second 
time they are of a pink color. 

Order Berberidaceae. — The Barberry Family. 
Herbs and shrubs with alternate or radical leaves ; 
flowers monoclinous or diclinous ; petals and sta- 
mens few ; carpels one to three, rarely more, 
distinct. Species about 100, mostly natives of cool 
climates. 

Berleris mdgaris, the Barberry of Europe (Figs. 550-3), is cultivated 
as an ornamental shrub, as well as for its edible acid berries. The 
flowers are interesting on account of their sensitive stamens, which 




Fig. 549.— Section of 
the young receptacle 
and carpels. 



RANALES. 



559 



move quickly toward the pistil when touclied at their bases hj an in- 
sect searching for the honej secreted by glands upon the petals (Figs. 
551-52). 

B. Canadensis, of the Southern States, is much like the foreign spe- 



FiGS. 550-3.— Illustrations of Berberis vulgaris. 




Fig. 



Fig. 551. 



Fig. 552. 



Fig. 553. 



Fig. 550.— Flower diagram. 

Fig. 551.— Pistil, with a petal and stamen. Magnified. 
Fig. 552.— Upper side of a petal, showing its two glands. 
Fig. 553.— Vertical section of ovary. Magnified. 



Magnified. 



Several evergreen species from the Rocky Mountains and Oregon, 
and one from Japan, are cultivated under the name of Mahonia. 

PodopTiyllum peltatum, the May Apple of the Eastern United States, 
produces an edible, plum-shaped fruit. Its poisonous rootstocks are 

Figs. 554-8.— Illustrations of Menispermum Canadense. 




Fig. 554. 



Fig. 555. 



Fig. 556. 



Fig. 557. Fig. 558. 



Fig. 554.— Diagram of male flower. Fig. 555.— Fruit. Magnified. 

Fig. 5.56.— Section of fruit. Magnified. Fig. 557.— Seed. Magnified. 

Fig. 558.— Section of seed. Magnified. 



used somewhat in medicine. A second species occurs in the Him- 
alayas. 

Caulophyllum tJialictroides, of the Eastern United States and also of 
Japan, is interesting on account of its young ovaries bursting open and 
allowing the ovules to develop into naked drupe-like seeds. 



5G0 



BOTANY. 



Order Menispermaceae. — Woody twining j^lants, with alternate 
leaves ; flowers diclinous ; petals usually six, wiili a stamen before 
(opposite to) eacli one; carpels usually three, distinct and one-seeded. 
Species eighty to one hundred, principally tropical. They generally 
contain a bitter principle, which in some is tonic, in others narcotic, or 
even poisonous. 

Menispermum Canadense, the Moonseed of the Eastern United 
States, is a beautiful climber deserving cultivation in ornamental gar- 
dens. Its only congener is a native of Eastern Asia. (Figs. 554-8.) 

Fiss. 559-64.— Illustkations of Asimina triloba. 




Fig. 561. 



Fig. 562. 



Fig. 563. 



Fig. 564. 



Fig. 5.59 —Section of flower. Magnified. 

Fig. 560.— Flower diagram. Magnified. Fig. 561. — Young carpel. Magnified. 

Fig. 562. — Section of young carpel. Magnified. 

Fig. 563.— Seed. Natural size. Fig. 564.— Section of seed. 



Two other genera, Calycocarjpum and Cocculus, are represented in 
the United States. 

Many of the Old World species are more or less in repute as furnish- 
ing medicines, but none are of sufficient importance to be particularly 
noticed. 

Order Anonacese. — Trees and shrubs with alternate leaves ; flowers 
trimerous ; stamens indefinite, on a thickened receptacle ; carpels gen- 
erally indefinite. Species 400, mostly tropical. The bark generally 
contains an aromatic and stimulating, sometimes acrid principle. 



BANALES. 



561 



Animina triloba, tlie Papaw of tlie Southern United States, and ex- 
tending to the Great Lakes, is a small tree producing edible pulpy 
fruits six to ten centimetres long. Several other smaller species of the 
same genus are common in the South. (Figs. 559-564.) 

Anona reticulata, the Custard Apple, A. Gherimolia, the Cherimoya, 
A. squamosa, Sweet Sop, and A. muricata, Sour Sop, all cultivated in 
the West Indies and tropical America, produce edible fruits ; the first is 
regarded by some people as one of the finest fruits in the whole world. 

Xylopia aromatica is a tree of western tropical Africa, whose dry 
carpels are aromatic, and used as pepper under the name of Guinea 
Pepper, The ancients used this pepper (" Piper ^thiopicum ") long 
before the introduction of Black Pepper. 

Figs. 565-7.— Illustrations of Magnolia purpurba. 




Fig. 566. Fig. 565. Fig. 567. 

Fig. 565.— Flower cnt vertically. Fig. 566.— Flower diagram. 

Fig. 567.— Section of seed. Magnified. 

J)uguetia quitarensis, a small tree of Guiana, supplies a tough elastic 
wood known as Lancewood. 

Order Magnoliacese. — The Magnolia Family. Trees and shrubs 
with alternate simple leaves ; flowers mostly monoclinous ; petals and 
stamens indefinite ; carpels usually indefinite. Species seventy, mostly 
of the tropical and sub-tropical parts of Asia and America. (Figs. 
566-7.) 

The genus Magnolia contains many beautiful trees, seven of which 
are natives of the Southern United States. Of these M. acuminata, the 
Cucumber Tree, extends north to the Great Lakes, and sometimes at- 



5G2 BOTANY. 

tains a lieij^lit of forty to fifty metres. Its light, wliitisli wood is valu- 
able, and is much used for many purposes. 

M. grandifloia is much like the preceding, but has larger flowers 
and evergreen leaves, the former being from fifteen to twenty- five 
centimetres in diameter. It grows only in the Southern States, where 
its timber is somewhat used. 

M. Umbrella and M. macrophylla are named Umbrella Trees on ac- 
count of the way in which their large leaves spread from the ends of 
the branches. The leaves of the last-named species are from fifty to 
eighty centimetres (20 to 30 in.) long, and the flowers are from thirty 
to thirty-five centimetres (12 to 14 in.) in diameter. 

M. glmca, the Sweet Bay, is a shrubby species extending from Louis- 
iana to Massachusetts, in the north near the coast only. 

The foregoing and most, if not all, the remaining species are quite 
ornamental, and are planted wh-^rever they will endure the winters. 

Liriodendron Tulipifera, the Tulip Tree or Yellow Poplar of the 
Eastern United States, is one of our largest and most valuable timber 
trees. Its light, wliitisli or yellowish wood is much used in cabinet- 
making, coach-building, and for many other purposes. 

Magnolia conspicua is the Yulan Tree of China. Other species of 
this genus occur in Japan, China, and the Himalaya region. 

Order Calycantliacese. — Shrubs with opposite leaves ; seeds with- 
out endosperm. Three species occur in the Southern United States, 
one in California, and one in Japan. This order, the structure of 
which cannot be discussed here, is evidently out of place in this Co- 
hort. 

Order Dilleniaceae. — Shrubs, rarely trees, with alternate leaves ; 
sepals five, petals five ; stamens indefinite ; ovaries usually distinct, one- 
celled. Species 180, mostly tropical. 

Two Californian species of the genus Grossosoma, doubtfully referred 
to this order, are our only representatives. 

Some of the Indian species of Dillenia and Wormia yield hard and 
valuable timber. 

Order Ranunculacese. — Herbs, rarely shrubs, with mostly alternate 
or radical leaves; sepals usually five or fewer, deciduous, often petal- 
oid ; petals in one whorl, often wanting ; carpels usually distinct. 
(Figs. 568-73.) Species about 500, most abundant in temperate and cold 
regions. The herbage usually possesses a considerable acridity. 

Formerly many of the species were reputed to be of medicinal value, 
but at the present day they are but little used except by quacks. Sev- 
eral species, however, still retain their places in the pharmacopoeias ; 
among these are : 

Aconitum Napellus, Monkshood or Aconite, a native of Europe, 
whose roots furnish the drug Aconite. 



UANALE8. 



563 



A. ferox, of upper India, supplies tlie people of fhat region with a 
virulent poison, with which they poison their arrows. 
Helleborus niger, Black Hellebore, H. foetidus. Slinking Hellebore, 



Figs. 568-73.— Illustrations of RANUNOULACBiE {Caltha palustris). 




Fig-. 568. 




Fig. 568.— Flowering stem. 
Fig. 570.— Flower diagram. 
Fig. 572. -Seed. Magnified. 




Fig. 570. 




Fig. 571. 



Fig. 572. 




Fig. 573. 

Fig. 569.— Vertical section of flower. 
Fig. 571.— Young carpel. Majjuified. 
Fig. 573.— Section of seed. Magnified. 



and H. viridis, Green Hellebore, all natives of Europe, furnish drastic 
and poisonous drugs. 

Among the ornamental plants of the order may be mentioned the 
following : 

Anemone, of several species, including our native Hepaticas, now 
placed in this genus. 



564 BOTANY. 

Adonis, the Pheasant's Eye, of Europe. 

Aquilegia, the Columbine, including our common Eastern species (^ 
Canadensis) and the Rocky Mountain Long Spurred Columbine {A 
ccerulea), as well as the common one of Europe {A. vulgaris). 

Clematis, the Virgin's Bower, of many species, native and foreign, all 
pretty. 

Delphinium, the Larkspur, of many species, mostly foreign. 

Nigella, Love in a Mist, from the Old World. 

PcPMiiia, the Peony, of several species, from Europe, Siberia, and 
China. 

Ranunculus, Buttercup, of several European species. 

Trollius, Globe Flower, from Europe and Siberia. 

Very few species afford nutritious products useful for food ; the 
tuberous roots of a species of Ranunculus are gathered and eaten in 
some parts of Central Europe, and a few fleshy species (as, for example, 
Caltlia palustris. Ranunculus sceleratus, etc.) are used to a limited ex- 
tent as pot herbs. 

Fossil Dicotyledons. — No Dicotyledons are known in the periods 
earlier than the Cretaceous. In this, however, many modern orders 
are represented. In the Cretaceous of the Western Territories of the 
United States Lesquereux describes* one hundred species of Dicotyle- 
dons. Of these sixty belong to the Apetalse, five to the Gamopetalae, 
and thirty-five to the Choripetalse (Polypetalae). The Apetalae incluae 
five species of Populus, six of Salix, eight of Quercus, six of Platanus, 
seven of Sassafras, etc. Among the remarkable fossils are a species of 
Ficus from Minnesota, two species of Cinnamomum from Kansas, and 
two oi Laurus from Nebraska. The five species of Gamopetalae repre- 
sent the Ericacese ('a single species of Andromeda), Ebenaceae (two spe- 
cies of Diospyros from Kansas and Nebraska), and Sapotaceae (two spe- 
cies, one a Bumelia from Nebraska and Minnesota). Among the spe- 
cies of Choripetalse are five of Magnolia, two of Liriodendron, one of 
Hedcra, one of Prunus, one of Pirus, etc., from Kansas, Nebraska, and 
Dakota. 

In the Tertiary most of the more important orders of Dicotyledons 
are represented. Here, as in the Cretaceous, there is still a predomi- 
nance of Apetalous species ; thus in the Tertiary Flora of the Western 
Territoriesf there have been determined of the Apetalae one hundred 
and twelve species, Gamopetalae, nineteen, and Choripetalae, sevent-"' 
nine. The Apetalae are principally represented by the Myricaceae 
(twelve species of Myrica), Betulacese, Cupuliferae (a Carpinus, a Coi'y- 
lus,& Fagus, a Casianea, and eighteen species of Quercus), Juglandaceae 



* " Contributions to the Fossil Flora of the Western Territories. 
Part I., The Cretaceous Flora," by Leo Lesquereux. Washington^ 
1874. 

f Leo Lesquereux, op. cit. Part II., "The Tertiary Flora," 1878. 



FOSSIL DICOTYLEDONS. 565 

(a Carya, a Pterocarya, and seven species of Juglans), Salicaceae (four 
species of Salix and twelve of Populus), Platanaceas (five species of 
Platanus), Moraceae (twenty-three species oi Ficus), Lauraceae (six spe- 
cies of Laurus^ one of Tetraiithera, and four of Cinnamomum). 

The Gamopetalae are represented by Caprifoliaceas (nine species of 
Viburnum), Oleaceae (four species of Fraxinus), Ebenacese (four species 
of Diospyros), and Ericaceae (an Andromeda and a Vaccinium). 

The principal orders of the Choripetalae are Ampelideae (one species 
of Ampelopsis, two of Vitis, and four of Cissus), Anacardiaceae (five 
species of Bhus), Cornaceae (four species of Cornua), Rliamnaceae (len 
species of Bhamnus, five of Zizyphus, three of Paliurus, and one ot 
Berchemia), Ilicineae (four species of Ilex), Sapindaceae (six species of 
Sapindu8), Myrtaceae (two doubtful species of Euadyptus), Rosacea^ 
(a single species of Gratmgus), Leguminosae (a Podogonium, a Cassia, an 
Acacia, a Mimosites, and two Leguminosites), and Magnoliaceae (four 
species of Magnolia). 



CHAPTER XXI. 

CONCLUDING OBSEEVATIONS. 

605.— The Number of Species of Plants. — It is impossible 
at the present time to give with even approximate accuracy 
the number of existing species of plants. In the first place, 
a great many species in all parts of the world are as yet un- 
described ; even in England, where the study of this branch 
of Botany has been most energetically pursued, many new 
species are discovered every year. In the central and western 
countries of the continent of Europe, as in England, while 
comparatively few flowering plants have escaped detection, 
there yet remain undescribed hundreds of species of the 
lower groups, an^ in the regions eastward there are doubtless 
many phanerogams as well as cryptogams which have not yet 
been enumerated. A complete "Elora of Europe" will 
probably be an impossibility for very many years. In Asia 
our knowledge of the plants is still more fragmentary. 
Japan and India, with parts of Asia Minor, are the best 
known botanically, but even in these regions our knowledge 
is almost entirely confined to the phanerogams and higher 
cryptogamSo In Australia and the islands to the northward 
and in Africa, there are enormous tracts which have not yet 
been explored. In the New World, from Mexico southward, 
the descriptions and enumerations of the native plants are 
scattered through many works, not one of which ap23roxi- 
mates completeness even for comparatively small regions. In 
North America, the "Flora of North America," begun fifty 
years ago, is yet unfinished, even for the flowering plants.* 

* " A Flora of North America/* by John Torrey and Asa Gray. Vol. 
1., 1838-40. Vol. XL (in part), 1843. Resumed under the title of "A 
Synoptical Flora of North America," by Asa Gray, 1878. 



i ' AFFINITIES OF THE GROUPS. 567 

I In the second place, many of tlie so-called species in de- 
Iscriptive works are but varieties, while in other cases the 

same forms have been described under different names. This 
|is true in all the groups of plants, and scarcely a monograph 
^now appears in which there are not cases of the reduction of 

a supposed species to a synonym or variety. 

606. — With these considerations in mind, we may examine 
the catalogues and make some general estimates. Steudel in 
1824 catalogued in ^^ j^omenclator Botanicus" 59,684 phan- 
erogams and 10,965 cryptogams, making a total of 70,649. 
I In the second edition, published in 1841, the number of 
phanerogams was increased to about 78,000. Lindley, in 
1845, estimated the number of dicotyledons to be 66,488, the 

i monocotyledons 13,952, and the cryptogams 12,480, making 
a total of 92,820. De Candolle's '' Prodromus," begun in 
1824 and continued to 1873, contains, according to Alph, De 
, Candolle's historical note in Vol. XVII. of that work, de- 
scriptions of 58,446 dicotyledons and 429 gymnosperms. 

Duchartre estimates the known species of phanerogams at 
about 100,000, and of cryptogams at about 25,000, and ven- 
tures to place the whole number of species in the world at 
from 150,000 to 200,000. Dr. Gray quotes De Candolle's 
estimate of the known species of flowering plants, amounting 
to from 100,000 to 120,000, and says that ''the larger num- 
ber may perhaps include the higher orders of the flowerless 
series," and in speaking of the lower cryptogams says that at 
present "no close estimate can be well formed of the actual 
number of species."* 

607.— The Affinities of the Groups of Plants.— Many at- 
tempts have been made to construct diagrammatic figures 
which should indicate th^ affinities of the different groups 
of the vegetable kingdom. While it is impossible to do this 
with any great degree of accuracy, we may yet show in this 
way certain relations, more clearly than can be done other- 
wise. The subjoined diagram may be taken to indicate in a 
general way the writer's present notion of the affinities {i.e., 

* In Ms " Botanical Text-Book," 1879, Part I., p. .34G, foot-note. 



5G8 



BOTANY. 



the genetic relations) of the seven great divisions of plants, 
so far as they can be shown upon a plane surface : 



Monocotyledones. 



ApetalcB. 



ChoripetalcB 



Dicotyledones. 



Gymnospekm^. 



Angiosperm^. 



.PHANERO- 
GAMIA. 



PTERIDOPHYTA. 



BRYOPHYTA. 



CARPOPHYTA. 

OOPHYTA. 



ZYGOPHYTA. 



PROTOPHYTA. 

608.— The Distribution of Plants in Time. If we bring 
together what is yet known as to Fossil Botany (Phytopalae- 
ontology), as has been done by Schimper,* we find that the 



* ** Traite de Paleontologie Vegetale," par W. Ph. Schimper. Paris, 
1869 to 1874. This work of three large octavo volumes (aggregating 
2696 pp.) and a quarto atlas of 110 plates is a most valuable one foU) 
the student of Phytopalaeontology. 



DISTRIBUTION IN TIME, 



5G9 



Tabulae, View of the Distribution in Time of the Divisions 
OP the Vegetable Kingdom. 



Kg 






















Recent. 


5h 






















Pliocene. 
















- 


Miocene. 
















- 


Eocene. 


'a 
a 
o 

1 














Creta- 
ceous. 
















Jurassic. 
















Triassic. 


c5 

1 

1 

a 

P-i 














Permian. 














Carbon- 
iferous. 














Devonian. 








( Gymnosperms. i 
< Monocotyledons. ; 
( Dicotyledons. *: 


Silurian. 


Protophyta. 

Zygophyta. 

Oophyta. 

Carpophyta. 

Bryophyta. 

Pteridophyta. 

Phanerogamia. 



570 BOTANY. 

several Divisions of the Vegetable Kingdom are very un- 
equally distributed in geologic time. Thus no fossil 
Protophyta have yet been discovered earlier than the Ter- 
tiary (Miocene), while the Zygophyta, Ooph3rta, and Carpo- 
phyta. with scarcely any doubt, were well represented in 
the Silurian. Bryophyta have not been detected in strata 
earlier than the Eocene (Tertiary), while Pteridophyta 
extend back to the Devonian. Of the Phanerogamia the 
Gymnosperms originated in the Devonian, the Monocotyle- 
dons in the Triassic, and the Dicotyledons in the Cretaceous. 
These facts may be more clearly shown by the table on the 
preceding page. 

It must be borne in mind that our knowledge of fossil 
plants is as yet extremely limited, a comparatively small 
portion only of the earth's strata having hitherto been care- 
fully examined. It is very probable that as we come to 
know more of the fossil remains of plants some or all of the 
lines in the table will be extended downward. On the other 
hand, we need not expect to find many remains of the ex- 
ceedingly simple organisms which constitute the Protophy- 
ta, althougli they probably have existed in abundance 
since pre-Silurian times. So, too, few Zygophytes have- a 
sufficiently durable plant-body to allow them to be preserved 
in a fossil state. The softness of texture and easy perisha- 
bility of the tissues of the Bryophyta, especially in the lower 
orders, probably accounts for the few fossil remains hitherto 
discovered. Doubtless we must in the same way account for 
the fact that most of the species of fossil Phanerogams are 
trees and shrubs ; the softer tissues of the herbaceous spe- 
cies have yielded but few fossils as compared with the harder 
and denser ones of the ligneous species. 



INDEX TO THE ILLUSTRATIONS. 



Abies pectinata, 394, 397, 401 

Acer dasycarpum, 74 

Acer Pseudo-Platanus, 536 

Achlya, 40, 255 

Achlya racemosa, 256 

Acorus calamus, 114, 115, 116 

Adiantum, 874 

Adiantum Capillus-Veneris, 370, 

371, 372 
Adiantum Moritzianum, 109 
^sculus, 537 

-3Ssculus Hippocastanum, 141 
A^aricus campestris, 326, 327 
Ailantlius glandulosus, 125, 448 
Alisma Plantagfo, 467 
Allium cepa, 423 
Alsophila, 377 

Ampelopsis quinquefolia, 154 
Anagallis arvensis, 507 
Ananassa sativa, 471 
Antlioceros laevis, 348, 350 
Arabis, 554 

Arcyria incarnata, 210 
Aristolocliia siplio, 84 
Asclepias, 504 
Ascobolus f urfuraceua, 288 
Asimina triloba, 560 
Aspidium Filix-mas, 41, 374, 375, 

876 
Asplenium, 374 

Bacillus ulna, 213 
Bacterium lineola, 213 
Bacterium Termo, 213 
Banana, 472 
Barbarea, 554 
Beet, 60, 495 
Begonia, 30 
Berberis vulgaris, 559 
Beta vulgaris, 495 
Betulaalba, 12(;, 127 
Biota orientalis, 396 



Bittersweet, 501 
Botrychium Lunaria, 378, 379 
Bryum argenteum, 359 
Buckwheat, 162 
Bulbochaete intermedia, 248 

Callitris quadrivalvis, 899 

Caltba palustris, 563 

Camellia Cbinensis, 548 

Canna, 473 

Capsella Bursa-pastoris, 424. 553 

Carya alba, 73 

Cassia tora, 533 

Castanea vesca, 158 

Cephalotus foUicularis, 527 

Cerastium collinum, 550 

Ceratozamia longifolia, 396 

Cbara fragilis, 382, 883 

Cbenopodium, 496 

Cherry, 148 

Chestut, 153 

Chondrioderme difforme, 36, 44, 

209, 21C 
Cichorium Intybus, 23 
Citrus Aurantium, 541 
Claviceps purpurea, 290 291, 
Clematis Viticella, 489 
Cnicus altissimus, 98 
Cocoa-nut, 468 
CofFea Arabica, 517 
Colcbicum autuinnale, 459 
Coleochaete pulvinata, 272 
Collema J acobafi folium, 800 
Colleina micropliylluui, 300 
Collema pulposum, 809 
Corallina oflBcinalis, 274 
Cosniariuiii Menenghinii, 44, 226 
Cucumis Melo, 521 
Cucurbita, 95 
Cucurbita Pepo, 29, 77 
Cnpiessus ,sem])ervirens, 896 
Cycas revoluta, 400 



57; 



INDEX TO THE ILLUSTRATIONS. 



Cypripediuin calceolus, 470 
Cystopus candidus, 259, 263 
Cytisus Laburnum, 84, 447 

Dahlia vARiABTLrs, 27, 33 

Date, 452, 463 

Diagrams, 33, 38, 138, 139, 403, 406, 

417, 420, 445, 450, 468 
Dictamnus fraxinella, 131, 542 
Didymium serpula, 78 
Dionsea muscipula, 525 
Dorstenia, 489 
Dracaena, 444 
Dudresnaya purpurifera, 276 

ECHINOCYSTIS LOB ATA, 30, 70, 71, 

73, 100, 155, 156 
Equisetum arvense, 365 
Equisetum limosum, 365 
Equisetum palustre, 110 
Equisetum scirpoides, 88 
Equisetum Telmateia, 364, 366 
Erica cinerea, 509 
Erysimum, 554 
Erysiplie Ciclioriacearum, 281 
Erysipbe Tuckeri, 279 
Eschsclioltzia Californica, 419 
Eucalyptus globulus, 524 
Eupatorium, 515 
Euphorbia, 75 
Eurotium repens, 282 

Fagoptrum esculentum, 162, 496 
Fern protballium, 370 
Ficus, 489 

Foeniculum vulgare, 519 
Fontinalis antipyretica, 87, 142, 359 
Fragaria vesca, 529 
Fritillaria imperialis, 3, 458 
Fuchsia globosa, 104, 105 
Fucus platycarpus, 266 
Fucus vesiculosus, 267 
Fuligo varians, 4, 209 
Funaria hy<rrometrica, 48, 52, 353, 
354, 356, 358 

Ginkgo btloba, 399 * 

Gleicbenia, 377 
Gloeocapsa, 216 
Gompbidium, 329 
Gordonia Lasiantbus, 547 
Grape, 79, 80 
Grapbis elegans, 309 

Hbdera helix, 130 



Hemlock Spruce, 152 
Hickory-nut, 73 
Hop, 97 

Horsecbestnut, 141 
Hoya carnosa, 34 
Hyacintbus orientalis, 101 
Hydrodictyon utriculosum, 223 
Hypericum calycinum, 549 

Iberis amara, 442, 443 
Impatiens Balsaznina, 28, 82, 543 
Indian Corn, 2. 6, 55, 67, 113, 154 

160, 451, 452 
Iridaceas (tiovver diagram), 468 
Isoetes lacustris, 387, 388 
Ivy, 130 

Juglans regia, 481 
J uncus effasus, 20 
Juniperus communis, 402, 407 

Lamium, 498 
Latbyrus odoratus, 531 
Latbyrus Pseudapbaca, 440, 441 
Laurus nobilis, 492 
Lavatera trimestris, 23 
Lecanora sublusca, 297 
Lejolisia mediterranea, 274, 275 
Lemua minor, 462 
Linum usitatissimum, 5'i4 
Lycopodium annotinum, 383 
Lycopodium clavatum, 383 
Lycopodium complanatum, 112 

Magnolia purpurea, 561 
.Mallotium Hildenbrandii, 303 
Malva sylvestris, 546 
Marcbantia polymorpba, 91, 92 

344, 345, 346, 347, 349, 350 
Marsilia Drummoudii, 381 
Megalospora affinis, 299 
Menispermum Canadense, 559 
Micrococcus prodigiosus, 213 
Mimosa pudica, 534 
Mucor, 33 S 
Mucor Mucedo, 236 
Mucor stolonifer, 237, 238 
Musa sapient um, 472 
Mustard, 95 
Myristica fra grans, 493 
Myrtus communis, 524 

Navicula saxonica, 229 
Navicula viridis, 228 
Nelumbium luteum, 558 



INDEX TO THE ILLUSTRATION'S. 



573 



Keraalion multifidum, 275 
Nepenthes ampullaria, 483 
Nitella flexilis, 331 
Nostoc, 37, 217 
Nupliar ad vena, 20 

Oat, 454 

Ochrolecliia pallescens, 299 

CEdogonium, 22, 247 

Qildogonium ciliatum, 248 

CEdogonium gemelliparum, 248 

Onion, 76 

Orchis mascula, 469 

Oscillatoria, 37, 217 

Osmunda, 377 

Palm (stem), 443 

Pandorina Morum, 222 

Papaver Rlioeas, 555 

Parmelia tiliacea, 302 

Peach (flower), 530 

Pediastrum granulatum, 65, 224 

Penicillium chartarum, 285 

Peronospora, 261 

Peronospora Alsinearum, 48, 261 

Peronospora calotheca, 258 

Peronospora infestans, 258 

Pertusaria ceuthocarpa, 299 

Pertusaria Wulf'eni, 309 

Peziza confluens, 286 

Peziza convexula, 42, 287 

Peziza omphalodes, 287 

Phaseolus multiflorus, 43, 475 

Phoenix dactylifera, 4o'3 

Phragmidiuni bulbosiim, 315 

Phragmidium mucronatum, 315 

Physarum leacopus, 208 

Physcia stellaris, 296 

Pilularia globulifera, 380 

Pinus Larico, 401 

Pinus pinaster, 72, 124 

]'inus Pinea, 405 

Pinus sylvestris, 25, 26, 394, 395, 

398 
Piptocephalis Freseniana, 239 
Pirus communis, 528 
Pirus Cydonia, 528 
Pi sum sativum, 54 
Plagiochilia asplenioides, 349 
Polypodium, 373 
Polypodium vulgare, 108 
Potamogeton pectinatus, 129 
Potato (flower), 501 
Primula sinensis, 97 
Prunus Cerasus, 530 



Psoralea bituminosa, 122, 476 
Pteris aquilina, 24, 27, 72, 81, S3, 

107. 371, 372, 373 
Puccinia graminis, 311, 313 
Puccinia Moliniae, 314 

QuTNCE, 528 

Quercus Robur, 449, 478 

Ranunculus repens, 119 

Rhizomorpha subcorticalis, 66 

Rhubarb, 60 

Riccia glauca, 345, 346 

Rice, 455 

Ricinus communis, 117, 118, 474 

Rosa canina, 427 

Rosa rubiginosa, 429 

Rye, 96 

SaCCHAROMYCES CEIIEVISI-.E, 39, 

214 
Salix caprsea, 486 
Salvinia natans, 380, 381 
Sambucus nigra, 445, 446 
Saprolegnia, 255 
Saprolegnia androgyna, 257 
Sarracenia purpurea, 557 
Schizgea, 377 
Scorzonera hispanica, 75 
Scrophularia, 499 
Sedum purpurascens, 101 
Selaginella caulescens, 384 
Selaginella inaequifolia. 111, 386 
Selaginella Maitensii, 384, 385 
Sequoia gigantea, 80 
Shepherd's Purse, 553 
Silphium laciniatum, 157 
Solanum, 501 

Sorosporium Saponariae, 320 
Sphaeria morbosa, 293 
Sphserophorus giobiferus, 298, 302 
Sphseroplea annulina, 245 
Sphaerotheca Castagnei, 280 
Sphaerotheca pannosa, 280 
Sphagnum acuti folium, 355 
Sphagnum squarrosum, 355 
Spirillum volutans, 213 
Spirochaete plicatilis, 213 
Spirogyra longata, 45, 46, 51, 233 
Stachys angustifolius, 441 
Sticta fuliginosa, 295 
Sticta pulmonacea, 30S 
Stipa spartea, 158 
SunHower, 68 



574 



INDEX TO THE JLLUST11ATI0N8. 



Taraxacum Dens leonis, 513 
Tax us baccata, 895 
Tetragonolobus, 531 
Theobroma Cacao, 545 
Thistle, 98 
Tilletia caries, 321 
Tradescantia Virginica, 12 
Trapa natans. 163 
Trichomanes, 377 
Tsuga Canadensis, 152 
Tuber melanosporum, 285 

Ulva, 224 

Uncinula adunca, 281 

Urtica macrophylla, 61 

Urtica urens, 491 

Usnea barbata, 302, 304, 308 

Ustilago antberarum, 320 

Ustilago Maydis, 320 



VaCCINIUM MYRTIIiLUS, 511 

Vanilla planifolia, 471 
Vaucheria sessilis, 47, 251, 252 

253 
Vibrio Rugula, 213 
Vicia faba, 38, 69, 474 
Viola tricolor, 20, 422, 423 
Virginia Creeper, 154 
Vitis, 79, 80 
Vitis vinifera, 538 
Vol vox globator, 244 

Wallflower, 552 
Welwitscbia mirabilis, 60, 414 

Yeast Plant, 39, 214 

Zea Mais, 113, 154, 160, 451, 452 



GENEBAL INDEX. 



Abele Tree, 497 

Abies, 81, 151, 394, 397, 409, 411, 

412, 415 
Abietinese, 410 

Abortion of Floral Organs, 431 
Abridgment of Life Cycle, 314 
Abronia, 497 
Absinthe, 514 

Absorption of Food, 176, 184, 191 
Acacia, 533, 534, 565 
Acanthacefce, 61, 499 
Acanthus Family, 499 
Accumbent Cotyledons, 437 
Acer, 72, 75, 535 
Acerinese, 119, 535 
Achene, 436 
Achenial Fruits, 436 
Achimenes, 499 
Achlamydeous, 431 
Achlya, 39, 256 
Achnanthes, 230 
Achnanthidium. 230 
Achromatiu, 16, 49 
Achyranthes, 496 
Acids, 62 
Acolium, 310 
Aconite, 562 
Aconitum, 106, 563 
Acorus, 58, 114, 462 
Acrocarpse, 359, 360 
Acroscyphus, 310 
Acrostichum, 377 
Actinocyclus, 231 
Actinodiscus, 231 
Actinomorphic, 430 
Actinoptychus, 231 
Acyclic Flowers, 429 
Adam's Needle, 461 
Adder Tongues, 373 
Adiantum, 110, 377 
Adlumia. Soft 



Adnate Anthers, 433 

Adnation of Floral Organs, 433 

Adonis, 53, 564 

Adventitious buds, 143 

Adventitious stems, 143 

^cidiospores, 312 

^cidium, 312, 316 

^gilops, 455 

Aerial roots, 137 

xEsculus, 537 

.Ethalium, 210 

^thusa, 520 

Alfinities of Plants, 567 

Agapanthus, 400 

Agarics, 241 

Agaricus, 39, 323, 328, 329, 330 

Agave, 467 

Ageratum, 98 

Aggregate fruits, 436 

Aggregations of cells, 65 

Agrimony, 149 

Agrostis, 455 

Ailanthus, 102, 541 

Air in the Plant, 174 

Albuminous seeds, 391, 437 

Albuminoids, 59 

Alders, 488 

Alectoria, 308 

Alectryon, 535 

Aleurites, 485 

Aleurone, 57 

Alfilaria, 543 

Alga, 133 

Al^se, 53, 55, 86, 135, 204, 305, 23t 

337, 340 
Algales, 837 
Alisma 4G7 

Alismaceffi. 128, 425, 466 
Alkaloids, 63, 182 
Alkanet, 502 
Allamanda, 504 



574 



INDEX TO THE JLLUBTMATIONS. 



Taraxactbi Denr-leonis, 513 
Tax us baccata, 395 
Tetragonolobus, 531 
Theobroma Cacao, 545 
Thistle, 98 
Tilletia caries, 321 
Tradescantia Virginica, 13 
Trapa natans. 163 
Tricbomanes, 377 
Tsuga Canadensis, 153 
Tuber melanosporum, 385 

Ulva, 334 

Uncinula adunca, 381 

Urtica macrophylla, 61 

Urtica urens, 491 

Usnea barbata, 303, 304, 308 

Usttlago antherarum, 330 

Ustilago Maydis, 330 



Vaccinium Myktillus, 511 
Vanilla planifolia, 471 
Vaucheria sessilis, 47, 351, 353 

353 
Vibrio Rugula, 313 
Vicia faba, 38, 69, 474 
Viola tricolor, 30, 423, 433 
Virginia Creeper, 154 
Vitis, 79, 80 
Vitis vinifera, 538 
Volvox globator, 344 

Wallflower, 553 
Welwitschia mirabilis, 60, 414 

Yeast Plant, 39, 314 

Zea Mais, 113, 154, 160. 451, 452 



GENERAL INDEX, 



Abele Tree, 487 

Abies, 81, 151, 394, 397, 409, 411, 

412, 415 
Abietinese, 410 

Abortion of Floral Organs, 431 
Abridgment of Life Cycle, 314 
Abronia, 497 
Absinthe, 514 

Absorption of Food, 176, 184, 191 
Acacia, 533, 534, 565 
Acanthaceae, 61, 499 
Acanthus Family, 499 
Accumbent Cotyledons, 437 
Acer, 72, 75, 535 
Acerineai, 119, 535 
Achene, 436 
Achenial Fruits, 436 
Achimenes, 499 
Achlamydeous, 431 
Achlya, 39, 256 
Achnanthes, 230 
Achnanthidium. 230 
Achromatiu, 16, 49 
Achyranthes, 496 
Acids, 62 
Acolium, 310 
Aconite, 562 
Aconitum, lOG, 562 
Acorus, 58, 114, 462 
Acrocarpse, 359, 360 
Acroscyplius, 310 
Acrostichum, 377 
Actinocyclus, 231 
Actinodiscus, 231 
Actinomorphic, 430 
Actinoptychus, 231 
Acyclic Flowers, 429 
Adam's Needle, 461 
Adder Tongues, 372 
Adiantum, 110,377 
Adluniia. 5.")6 



Adnata Anthers, 433 

Adnation of Floral Organs, 433 

Adonis, 53, 564 

Adventitious buds, 143 

Adventitious stems, 143 

^cidiospores, 312 

^cidium, 312, 316 

^gilops, 455 

Aerial roots, 137 

^sculus, 537 

x^thalium, 210 

.Ethusa, 520 

Affinities of Plants, 567 

Agapanthus, 4G0 

Agarics, 241 

Agaricus, 39, 323, 328, 329, 330 

Agave, 467 

Ageratum, 98 

Aggregate fruits, 436 

Aggregations of cells, 65 

Agrimony, 149 

Agrostis, 455 

Ailanthus, 102, 541 

Air in the Plant, 174 

Albuminous seeds, 391, 437 

Albuminoids, 59 

Alders, 488 

Alectoria, 308 

Alectryon, 535 

Aleurites, 485 

Aleurone, 57 

Alfilaria, 543 

Alga, 133 

Algse, 53. 55, 86, 135, 204, 205, 22t 

337, 340 
Algales,337 
Alisma 4G7 

Alismace^e, 128, 425, 466 
Alkaloids, 02, 182 
Alkanet, 502 
Allamanda, 504 



57G 



GENERAL INDEX. 



Alligator Pear, 494 

Allium, 458 

Allspice, 523 

Almond, 530 

Alnus, 488 

Aloe, 458 

Aloes, 459 

Alsoplnla, 377 

Alternate leaves, 149 

Alternation of Generations, 341, 

361 
Altlij3ea, 547 
Alyssum, 98, 554 
Axnarantaceic, 496 
Amarantus, 264, 496 
Amaryllidace8e,461, 467 
Amaryllis, 468 
Amaryllis Family, 467 
Amaurocliseteye, 210 
Ambrosia, 264, 429, 515 
Amelancliier, 527 
Amentales, 485 
Aments, 413 
American Larcli, 412 
American White Ash, 505 
American White Elm, 488 
Ammonia Salts, 176 
Amoeba movement, 8 
Amole, 468 
Amomales, 471 
Amoreuxia, 551 
Amorphophallus, 462 
Amount of Evaporation, 171 
Amount of Water in Plants, 166 
Ampelidese, 537, 565 
Ampelopsis, 165, 194, 538, 565 
Amphio-astria, 344, 351 
Ampliipleura, 230 
Amphora, 230 
Anacardiacese, 534, 565 
Anacardium, 535 
Anacliaris, 473 
Anaesthetics, 198 
Anagallis, 434, 436, 507 
Analoo-y and Homology, 120 
Ananagsfi, 471 
Anastatica, 555 
Ancestry of Plants, 204 
Anchusa, 502 
Andrgea, 358 
Andraeaceae, 355, 358 
Androecium, 418, 430, 432 
Androgynia, 250 
Andromeda, 564, 565 



Andromedeae, 510 

Androspore, 249 

Anemeae, 210 

Anemone, 102, 264, 284, 429, 563 

Anemia, 377 

Anemiopsis, 483 

Anemophilous Flowers, 421 

Angi(jcarpous Lichens, 297, 398 

Angiopteris, 378 

Anjriospermae, 393, 416, 568 

Anoiosperms, 79, 85 

Angular divergence of leaves, 150 

Angustura Bark, 542 

Aniseed, 520 

Annual layers of wood, 447 

Annular Vessels, 118 

Annulus, 328, 375 

Anona, 561 

Anonaceae, 560 



Anorth( 



50 



Anthemideae, 514 
Antliemis, 514 
Anther, 394, 417, 418 
Antheridial disc, 347 
Antheridium, 45, 243, 266,271, 331, 

341, 361 
Anther Smut, 318 
Anthesis, 199 

Anthoceros, 11, 217, 341, 348, 350 
Anthoceroteae, 350, 361 
Antiaris, 490 
Antipodal Cells, 420 
Antirrhinum, 150, 500 
Apetalae, 476, 568 
Apetalous, 431 
Aphyllon, 192 
Apical Cell, 38, 86, 88, 153, 343. 

352, 363, 373, 378, 380, 381, 425 
Apium, 519 
Appendages, 281 

Apple, 64, 159, 171, 284, 436, 527 
Apocarpous, 433 
Apocynaceae, 77, 119,504 
Apocynum, 504 
Apostasiaceae, 469 
Apothecium, 297 
Apricot, 62, 530 
Aqueous Tissue, 94 
Aquilegia, 564 
Arabis, 437 

x\raceae (=Aroideae), 77 
Arachis, 532 
Arachnoidiscus, 231 
Arales, 461 



GENERAL INDEX. 



57^ 



Aralia, 519 

Araliaceae, 519 

Araucaria, 409, 413, 414 

Araucarieae, 413 

Arbor Vitae, 411 

Arbutus, 509 

Arceutliobium, 477 

Arcbas, 506 

Arcbegonium, 46, 341, 361, 403 

Arcbespermae, 393 

Arcbidium, 358 

Arcbimycetes, 339 

Arctopodium, 385 

Arctostapbylos, 156, 509 

Arctoidese, 514 

Arcyria, 211 

Areca, 466 

Arecinese, 466 

Aretbusa, 470 

Aretbusese, 470 

Argemone, 556 

Aril, 437 

Arissema, 61, 462 

Aristolocbia, 482 

Aristolocbiacese, 483 

Arineria, 508 

Arnica, 514 

Arnotto, 551 

Aroide*, 119, 461 

Aroids, 461 

Arrack, 464 

Arrangement of Leaves, 149 

Arrangement of Roots, 164 

Arrowroot, 473, 484 

Artemisia, 85, 514 

Artbonia, 310 

Ariboniei, 310 

Articboke, 512, 515 

Artocarpus, 489 

Arum Family, 461 

Asafoetida, 63, 520 

Asarales, 482 

Asarum, 482 

Asclepiadacese, 77, 119, 503 

Asclepias, 102, 426 

Ascobolus, 288, 289, 301 

Ascogouium, 300 

Ascomy cetes, 214, 270, 271, 273, 278, 

305, 323, 335, 337, 338, 340 
Ascospores, 40, 214, 278, 315, 319 
Ascus, 278, 315, 319 
Ascyrum, 549 

Asexual Generation, 341, 361 
Asb, 436 



Asb Tree, 505 

Asimina, 561 

Asparagus, 458 

Aspergillus, 284 

Aspbodel, 460 

Aspbodelus, 460 

Aspidium, 377 

Asplenium, 377 

Assimilation, 62, 178, 185, 191 

Astepbanse, 334 

Aster, 516 

Asterales, 512 

Asteroideae, 516 

Asterolampra, 231 

Asterolampreae, 231 

Asteropbyllites, 368 

Astilbe, 526 

Astragalus, 532 

Astrocaryum, 17 

Astrotrichia, 520 

Asymmetry of Leaves, 146 

Atalea, 464 

Atberosperma, 494 

Atmospberic pressure, 171 

Atricbum, 352 

Atriplex, 52 

Atropa, 502 

Aucuba, 518 

Aulacodiscus, 231 

Auliscus, 231 

Aurantieae, 541 

Auricula, 506 

Australian Pitcber Plant, 526 

Austrian Pine, 412 

Autogamous Flowers, 421 

Autumn Crocus, 460 

Auxospores, 228 

Avena, 102, 455 

Avocado Pear, 494 

Axile Placenta, 433 

Azalea, 510 

AzoUa, 381, 382 

Baccate Fruits, 436 
Baccate Seeds, 437 
Bacillariaceae, 227 
Bacillus, 213 
Bacteria, 65, 212 
Bacteriaceffi, 212, 339 
Bacterium, 17, 213 
Bactrospora, 298 
HsBomyces, 310 
Balanopboreae, 476 
Bald Cypress, 411 



678 



GENERAL INDEX. 



Balloon Vine, 537 

Balm, 498 

Balsam, 61, 94, 144, 543 

Balsam Apple, 522 

Balsam Fir, 412 

Balsamodendron, 540 

Balsam of Peru, 532 

Balsam of Tolu, 532 

Bamboo, 453, 457 

Bambusa, 457 

Banana, 146, 472 

Banana Family, 471 

Bauds of Protoplasm, 16 

Banksia, 491 

Banyan Tree, 490 

Baobab, 474 

Bapliia, 532 

Barberry, 197, 316, 558 

Barberry Cluster Cups, 316 

Barberry Family, 558 

Barberry Rust, 316 

Barbula, 351, 360 

Barcelona Nuts, 477 

Bark, 118, 124, 201, 393, 409, 447 

Barley, 59, 187, 319, 322, S23, 455 

Barosma, 542 

Bartramia, 359 

Basal Cells, 206 

Basellacese, 494 

Basidia, 323 

Basidiomycetes, 270, 323, 335, 337, 

338, 340 
Basidiospores, 39, 323, 328 
Bassia, 506 
Bassorin, 63 
Basswood, 545 
Bast Cells, 17 
Bast Fibres, 74, 76, 119 
Bast, Soft, 116 
Batliybius, 15 
Batrachospermeae, 277 
Bay berry, 487 
Bay Tree, 493 
Bdellium, 465, 540 
Bean, 56, 58. 59, 199, 435, 581 
Bearberry, 509 
Bear Grass, 461 
Bedfordia, 514 
Bedstraw, 517 
Beech, 125, 126, 421, 479 
Beech Mast, 479 
Beech Nuts, 479 
Beet. 166, 495 



Begonia, 01, 94, 143, 146, 5^1 

Be<roniace8e, 71, 521 

Belladonna, 502 

Bellis, 516 

Berberidaceae, 558 

Berberis, 85, 102, 558 

Bercbemia, 565 

Berry, 436 

Bertiiolletia, 58, 523 

Beta, 103, 495 

Betel Nut, 466 

Betel Palm, 466 

Betel Pepper, 484 

Betula, 102, 174, 487 

Betulacese, 487, 564 

Bhano-, 488 

Biatora, 310 

Bicol lateral Bundles, 121 

Bicyclic, 430, 432 

Biddulphia, 231 

Biddulphieae, 231 

Bidens, 264, 515 

Bio:nonia, 81, 85, 426, 499 

Bignoniaceae, 499 

Bio- Trees of California, 411 

Bilaterality of Leaves, 146 

Bilocular, 433 

Biota, 409 

Bi parous Cyme, 429 

Birch, 126, 174, 421, 437, 487 
Birch Family, 487 

Bird Cherry, 530 

Birds Aiding in Pollination, 421 

Bisexual Flowers, 431 

Bittersweet, 539 

Bixia, 551 

Bisineae, 551 

Black Ash, 505 

Blackberry, 426, 437# 529 

Black Bindweed, 497 

Black Grain, 532 

Black Huckleberries, 511 

Black Jack Oak, 480 

Black Knot. 292 

Black Nightshade, 502 

Black Oaks, 480 

Black Pepper, 483, 561 

Black Rust, 316 

Bladder-nut, 535 

Bladderwort Family, 499 

Blanching of Celery, 53 

Blanc Mange, 277 

Blazing Star, 516 



GENERAL INDEX, 



579 



Bleeding Heart, 556 

Bletia, 470 

Blood-root, 556 

Bloodwood Tree, 523 

Bloodwort Family, 467 

Blueberry, 511 

Blue Beech, 477 

Blue Guu), 524 

Blue Huckleberries, 511 

Blue Mould, 285 

Blue Palmetto, 465 

Bluets, 517 

Bocconia, 556 

Boehmeria, 491 

Boletus, 330 

Bombax, 547 

Borage Family, 503 

3orassine8e, 465 

Borassus, 46f 

Bordered Pits, 251 

Bore Cole, 553 

Boronieae, 542 

Borraginacese, 150, 503 

Bostryx, 429 

Boswellia, 540 

Boirycbium, 379, 380 

Botrydium, 134 

Botry-Cyme, 429 

Botryose Inflorescence, 427, 428 

Botryose Monopodium, 140 

Bouncing Bet, 550 

Boundary Tissue, 89 

Boussingaultia, 494 

Bouvardia, 518 

Bow- wood, 490 

Box Elder, 536 

Box Tree, 485 

Bracts, 136, 155 

Bran-cell, 58 

Branching, Modes of, 139 

Branching of Leaves, 147 

Branches of Stems, 142 

Brassica, 98, 102, 150, 553 

Brazilian Arrowroot, 484 

Brazilian Artichoke, 515 

Brazil Nut, 58, 524 

Brazil wood, 533 

Bread-Fruit Tree, 489 

Break- Ax Tree, 545 

Bristles, 137 

British Oak, 479 

Bromeliaceae, 471 

Brompton Slack, 554 

Broom Corn, 457 



Brosimum, 489, 490 
Broussonetia, 490 
Bruchia, 358 
Brucia, 503 
Bruniacese, 526 
Brussels Sprouts, 553 
Bryaceae, 355, 358 
Bryophvllum, 143, 526 
Bryophyta, 205, 305, 341, 568, 569, 

570 
Bryophytes, 10, 40, 59, 67, 73, 87, 

90, 124, 140, 143, 145, 265, 341. 

389 
Bryum, 352, 359, 360 
Buchu, 542 
Buckeye, 537 
Buckthorn, 539 
Buckwheat, 496 
Buckwheat Family, 496 
Buckwheat Tree, 539 
Bud, 139, 140, 181, 189, 199 
Bud-cell, 332 
Buellia, 310 
Buflfalo Berry, 492 
Bulb, 181, 190, 191 
Bulb-axes, 136 
Bulbochsetaceae, 269 
Bulbocheete, 250 
Bulbophyllum, 471 
Bulgaria, 289 
Bumeliu, 506, 564 
Bundles, Fibro- vascular, 106 
Bundle Sheath, 108, 114 
Bunt, 318 

Burgundy Pitch, 412 
Burmanniact^ae, 468 
Burning Bush^ 639 
Bursera, 540 
Burseraceae, 540 
Bush Honeysuckle, 518 
Butcher's Broom, 461 
Buttercup, 564 
Butternut, 482 
Butter Trees, 506 
Button Bush, 517 
Button wood, 487 
Buxus, 102, 485 

Cabbage, 93. 171, 185 
Cal)bage Palmetto, 505 
Cacalia, 514 
Cachibou, 540 
CactMceae, 94, 520 
Cacti, 503 



580 



GENERAL INDEX. 



Cactus Family, 520 

Caelosphaerium, 316 

Caesalpina, 533 

Caesalpiniea?, 533 

Caffeine, 183 

Calabash Tree, 499 

Calamandar Wood, 506 

Calamariese, 368 

Calamese, 465 

Calauiites, 368 

Calamocladus, 368 

Calamostacliys, 368 

Calamus, 81, 465, 466 

Calandrinia, 549 

Calcarese, 210 

Calceolaria, 500 

Calcium, 175 

Calcium Carbonate, 60 

Calcium Oxalate, 59, 180 

Calendulacese, 514 

Caliciacei, 310 

Caliciei, 310 

Calicium, 310 

California Laurel, 494 

California Pitcker Plant, 557 

Calla, 61, 462 

Calla Lily 462 

Call i ops: s, 514 

Callirhoe, 547 

Callistephus, 516 

Callithamnion, 277 

Callitris, 399,411 

Calluna, 509 

Calocasia, 462 

Calonemese, 211 

Calopbyllum, 549 

Calopogon, 470 

Caltha, 436, 564 

Calycanthacese, 562 

Calyceraceae, 516 

Calycocarpum, 560 

Calypso, 471 

Calyx, 418, 430 

Cambium, 17, 116, 121, 143, 164, 

201,407, 444 
Cambiform Cells, 111 
Camelina, 554 
Camellia, 548 
Cam pan ales, 511 
Campanula, 13, 512 
Campanulaceae, 77,119, 511 
Camphor, 63, 494, 547 
Camphor Tree, 547 
Camwood, 532 



Canada Balsam, 412 

Canada Thistle, 513 

Canal, Intra-fascicular, 111 

Candle Nut Tree, 485 

Candytuft, 554 

Caneila, 551 

Canella Bark, 551 

Canellacese, 551 

Cane Palms, 465 

Cane Sugar, 62, 180 

Canna, 473 

Cannabis, 488 

Cannabineae, 488 

Cannaceae, 425 

Cannjfi, 473 

Canon Live-Oak, 479 

Canterbury Bells, 512 

Caoutchouc, 78, 485, 490, 503, 504 

Capers, 552 

Capillitium, 210 

Capparidacese, 5o2 

Capparis, 552 

Caprifoliaceae, 518, 565 

Capsella, 98, 264, 425, 554 

Capsicum, 501 

Capsulary Fruits, 436 

Capsule, 348, 355, 436 

Caragana, 532 

Caraway, 520 

Carbon, 175 

Carbonates, 176 

Carbohydrate, 178 

Carbon Dioxide. 174, 181, 191 

Carbon Oxide, 179 

Carcerulus, 436 

Cardinal Flower, 512 

Cardiospermum, 537 

Carex, 150, 323 

Carica, 522 

Carludovica, 462 

Carnations, 5'i0 

Carnivorous Plants, 182 

Carmine, 520 

Carpel, 136, 430, 433 

Carpellary Leaves, 400 

Carpet- weed, 520 

Carpids, 433 

Carpinus, 477, 564 

Carpogonium, 271, 300, 380, 331 

Carpophore, 436 

CarpoDhyllum (pl.-la,^ 419, 433 

Carpospore, 332 [568, 569, 570- 

Carpopbyta, 205, 270, 335, 337, 339,. 

Carpophytes, 389 



OENEBAL INDEX. 



581 



Carrot, 519 

Cartbamus, 512 

Carya, 78, 482, 565 

Caryopbyllacese, 494, 549 

Caryophyllales, 549 

Caryopsis, 436 

Caryota, 466 

Cascarilla Bark, 485 

Cashew Family, 534 

Cashew Nut, 535 

Cassava, 484 

Cassia, 197, 533, 565 

Cassia Bark, 494 

Cassia Buds, 494 

Castanea, 478, 564 

Castilleia, 53 

Castilloa, 490 

Castor Bean, 59, 181 

Castor Oil, 62 

Castor Oil Plant, 475, 484 

Casuarinege, 487 

Catalpa, 429, 437, 499 

Catasetum, 470 

Catchfly, 550 

Catha, 539 

Catkin, 395, 413, 428 

Catnip, 498 

Cattleya, 471 

Caulerpa, 134, 254 

Caulerpites, 254 

Caulicle, 404 

Cauliflower, 553 

Cauline Bundles, 392, 442 

Caulome, 134, 135, 243, 271 

Caulophyllum, 559 

Cayenne Pepper, 501 

Ceanothus, 61, 103 

Cedrelia, 540 

Cedrus, 409, 415 

Celastracese, 539 

Celastrales, 537 

Celastrus, 539 

Celery, 519 

Cell Derivatives, 67 

Cell Families, 65 

Cell Formation by Division, 36 

Cell Formation by Union, 44 

Cell Fusions, QQ 

Cell Masses, 67 

Cell Rows, 67 

Cell Sap, 62 

Cell Surfaces, 67 

Cellular Plants, 205 



Cell Wall , 15, 21, 68, 166, 206 

Celosia, 496 

Celtis, 61, 85, 150, 488 

Cellulose, 21 

Cenangium, 289 

Centaurea, 513 

Central Cell, 331, 375 

Centrifugal Thickening, 31 

Centripetal Thickening, 31 

Century Plant, 467 

Cepbaelis, 517 

Cephalantbus. 517 

Cephalotus, 526 

Ceramieae, 277 

Ceramium, 278 

Cerasin, 68 

Cerastium, 429, 550 

Ceratopbyllese, 483 

Ceratozamia, 410 

Cercis, 533 

Cercocarpus, 529 

Cereus, 520 

Cereal Grains, 181 

Ceropegia, 503 

Ceroxyion, 93, 466 

Cestrum, 502 

Cetraria, 308 

Chaetocerese, 281 

Chaetoceros, 231 

Cbsetocladium, 241 

Cbailletiacese, 540 

Cbamaebatia, 529 

Chamsecyparis, 411 

Chamsedorea, 466 

Chamaerops, 465 

Chamomile, 514 

Channels in Cell- Walls, 24 

Chaptalia, 512 

Chara, 14, 333. 334 

Cbaraceoe, 271, 331, 335, 837, 340 

Charese, 833, 884 

Charlock, 554 

Charopbyta, 840 

Checkerberry, 510 

Cheiranthus, 554 

Chelura, 524 

Chemical Processes in Cells, 168 

Chemical Processes in the Plant, 

178 
Chemical Rays of Spectrum, 192 
Chenopodiaceae, 495 
Chenopodiales, 494 
Chenopodium, 71, 102, 436, 495 



58;^ 



GENERAL INDEX. 



Cherimoya, 561 

Cherry, 62, 64, 126, 143, 159, 284, 

292, 426, 428, 436, 580 
Cherry Blight, 140 
Cherry Laurel, 173 
Chestuut, 58, 154, 421, 478 
Chibou, 540 
Chicory, 512 
Chimaphlla, 510 
China Aster, 516 
China Grass, 491 
Cliiuese Date, 506 
Chinese Primrose, 506 
Chinese tiugar-Cane, 457 
Chinese Yam, 467 
Chiodecton, 310 
Chiouauthus, 505 
Chittagoug Wood, 540 
Chlasuaceae, 547 
Chlamydospores, 237 
Chlorantliacese, 483 
Chlorides, 176 
Chlorine, 175 
Chlorococcum, 219 
Chlorophycese, 339 
Chlorophyll, 50, 70, 94, 155, 178, 

191, 205, 206 
Chlorospermeae, 337 
Chloroxylon, 540 
Chocolate, 546 
Chocolate Tree, 545 
Chondrites, 278 
Chondrus, 277 
Choripetalse, 476, 518, 568 
Choripetalous, 431 
Chorisepalous, 431 
Chowlee, 532 
Chromatin, 16, 49 
Chronizoospores, 223 
Chroococcacese, 216, 305, 306, 339 
Chroococcus, 216 
Chroolepideae, 306 
Chrysanthemum, 514 
Chrysobalanese, 530 
Chrysophyllum, 506 
Chufa, 457 
Churrus, 488 
Chylocladieae, 277 
Cichoriacese, 67, 77, 78, 119, 512 
Cichorium, 512 
Cicinnus, 429 
Cicuta, 520 
Cilia, 10 
Ciliary Movement, 10 



Cinchona, 17, 64, 182, 517 

Cineraria, 514 

Cinuamomum, 494, 564, 565 

Cinnamon, 494 

Circinella, 237 

Circumcissile Dehiscence, 435 

Circulation of Protoplasm, 14 

Cissus, 482, 538, 565 

Cistaceee, 552 

Cist us, 552 

Citric Acid, 64, 182 

Citron, 541 

Citrullus, 522 

Citrus, 541 

Cladouia, 306, 309 

Cladoniei, 309 

Cladophora, 10, 37, 224, 245, 306 

Cladoxylon, 415 

Classihcatiou, 202 

Clavaria, 330 

Claviceps, 289. 294 

Claytonia, 199, 549 

Cleavers, 517 

Cleistogamous Flowers, 421 

Clematis, 564 

Cleome, 552 

Clerodendron, 498 

Clethra, 510 

Cliftonia, 539 

Climacospheuia, 231 

Climacium, 360 

Climbing Bittersweet, 539 

Closed Bundle, 121, 443 

Closing of Flowers, 199 

Closterium, 11, 227 

Clove Pink, 93, 550 

Clover, 197, 428, 532 

Cloves, 523 

Clove Tree, 523 

Cluster Cups, 316 

Cuicus, 513 [190 

Coagulation of Albuminoids, 188, 

Coalescence of Floral Organs, 432 

Coats of Ovule, 401 

Cobsea, 503 

Cob-nuts, 477 

Cocciospermese, 340 

Coccoueis, 230 

Cocconideae, 230 

Cocculus, 560 

Coccus, 490 

Cochineal Insect, 520 

Cockleburs, 515 

Cockscomb, 496 



GEKEHAL INDEX, 



583 



Cocoa, 546 

Cocoanut, 464 

Cocoineae, 464 

Cocos, 464 

Cceloblastese, 250, 269, 336, 337 

Ccelogyne, 471 

Coenobia, 221 

Coenooroniei, 310 

Coenogonium, 310 

CofEea, 517 

Coffee, 182, 517 

Cohorts of Dicotyledons, 476 

Cohorts of Monocotyledons, 453 

Coix, 93 

Colchicum, 460 

Coleochaetacese, 339 

Coleochaete, 271, 274, 279, 335, 337 

Coleochaeteae, 339 

Coleus, 52, 498 

Collar, 475 

Collateral Bundle, 120, 362, 368, 

380, 392, 438 
Collema, 295, 298, 300, 301, 805, 

306, 309 
Collemaceae, 305 
Collemei, 309 
Collenchyma, 29, 70, 89. 124, 363, 

378, 392 
Collum, 475 
Colocyntb, 522 
Coloring Matters, 64 
Colors of Flowers, 53 
Columbine, 564 
Columella, 210,236, 360 
Columelliaceae, 499 
Columelli ferae, 211 
Colza, 554 
Comandra, 476 
Combretaceae, 524 
Commelynaceae, 457 
Commelynales, 457 
Common Bundles, 368, 392, 438 
Comose Seeds, 437 
Compass Plant, 103, 156, 515 
Complete Flower, 431 
Compositge, 62, 94, 99. 197, 284, 425, 

429, 434, 512 
Composites, 153, 158 
Compound Leaves, 147 
Compound Pistil, 433 
Compound Raceme, 42*3 
Compounds in Plant-Food, 176 
Compound Spike, 428 
Compound Umbel, 428 



Concentric Bundle, 120, 362 

Conceptacles, 265 

Concluding Observations, 566 

Conducting Tissue, 89 

Cone, 397 

Conepia, 531 

Conferva, 37, 306 

Confervacese, 224, 245, 277 

Confervites, 242 

Confervoidese, 339 

Conjugatae, 225, 242, 336, 340 

Conjugation, 45, 47, 225 

Conia, 182 

Conidia, 39, 241, 260, 273, 279, 

289, 292, 294, 312, 315, 323, 357 
Coniferae, 25, 51, 130, 132, 396, 409, 

410, 415 
Conifers, 143, 153, 158, 409, 410 
Coniocybe, 310 
Coniomycetes, 338 
Conium, 182, 520 
Connaraceae, 534 
Connarus, 534 
Connecting Tube, 276 
Connective, 433 
Conotrema, 309 
Constituents of Plants, 166 
Convallaria, 460 
Conversion into Mucilage, 35 
Convolvulaceae, 77, 502 
Convovulus, 502 
Copaifera, 533 
Copaiva Balsam, 533 
Copai-ye Wood, 550 
Copernica, 464 
Coprinus, 329, 330 
Coquilla-nuts, 464 
Corallina, 277, 278 
Corallines, 277,278 
Corallorhiza, 192, 471 
Corchorus, 545 
Cordate Leaves, 146 
Coreopsis, 514 
Coriander, 520 
Coriarieae, 534 
Cork, 125, 480 
Cork Cambium, 126 
Cork Oak, 125, 480 
Cork -wood, 547 
Corm, 136 

Cormophyta, 203, 205 
Cormophytes, 335 
Cornaceae, 518, 565 
Corn Cockle, 5,**0 



584 



GENERAL INDEX, 



Cornus. 518, 505 

Corolla, 418, 430 

Corpuscula, 393, 403 

Cortex, 201 

Coryleae, 477 

Cory 1 us, 477, 564 

Corymb, 428 

Corynospermeae, 340 

Corypliinese, 464 

Coscinodisceae, 231 

Coscinodiscus, 11, 231 

Cosmarium, 44, 227 

Cotton, 98, 437, 546 

Cottonwood, 487 

Cotyledon, 526 

Cotyledons. 386, 391, 404, 424 

Couma, 504 

Cowslip, 506 

Cow Tree, 489 

Crab-Apples, 527 

Cranberry, 511 

Crape Myrtle, 523 

Crassula, 526 

Crassulaceae, 526 

Crataegus, 527, 565 

Cratoxylon, 549 

Crayfishes, growths on, 257 

Cremocarp, 436 

Crenate Leaf, 147 

Creosote Busli, 543 

Crescentia, 499 

Cribraria, 211 

Crocus, 56, 468 

Crossosoma, 563 

Crotallaria, 533 

Croton, 484, 485 

Croton Oil, 484 

Crown Imperial, 460 

Crucibulum, 325, 326 

Cruciferge, 98, 181, 264, 425, 553 

Crucifer Family, 553 

Cryptogam, 204, 271, 316 

Cryptogamia, 204, 205 

Cryptomeria, 411 

Crypt onemieee, 277 

Crypto-Rapliidieae, 231 

Crystalloids, 57, 58 

Crystals, 57, 59 

Cuba Bast, 547 

Cubebs, 484 

Cuboidal Cell, 19 

Cucumber, 522 

Cucumber Tree, 561 



Cucumis, 14, 80. 533 
Cucurbita, 11, 13, 14, 35, 53, 80, 85, 
532 [531 

Cucurbitaceae, 39, 51, 71, 130, 181, 
Cucurbitaria, 294 
Cultures of Lichens, 307 
Cultures of Moulds, 239 
Cultivated Plants, 182 
Cummin, 520 
Cupania, 537 
Cupbea, 523 
Cupresseae, 411 
Cupressus, 409, 411 
Cups, 136 

Cupuliferae, 425, 426, 477, 564 
Curare, 503 
Curcuma, 472 
Currant, 64, 526 
Cuscuta. 56. 502 
Cuspariese, 543 
Custard Apple, 561 
Cuticle, 34, 93 
Cuticularizing, 35 
Cyanophycese, 215, 336, 339 
Cyathea, 377 
Cyatlieaceae, 376 
Cycadeae, 409, 410 
Cycads, 409, 410, 416 
Cycas, 399, 410 
Cyclamen, 506 
Cyclic Flowers, 429. 430 
Cyclotella, 231 
Cvdonia, 527 
Cylindrical Ceil, 19 
Cymatopleura, 231 
Cymbella. 230 
Cymbelleee, 230 
Cyme, 429 
Cymo-Botrys. 429 
Cymose Inflorescence, 427, 429 
Cymose Monopodium, 140 
Cynara, 573 
Cynaroideae, 513 
Cynips, 479 
Cynoglossum, 57 
Cynomorium, 476 
Cyperaceae, 457, 473 
Cyperus, 457 
Cypress, 411 
Cypripedieae, 40^ 
Cypripedium, 469 
Cyrilla, 539 
Cyrillaceae, 539 



GENERAL INDEX, 



685 



Cystidia, 328, 330 
Cystoliths, 60 
Cystopteris, 377 
Cvstopus, 39, 260, 264 
Cytisus, 85, 532 

Dacrymyces, 289 

Dactylina, 308 

Dactylis, 455 

Daffodil, 468 

Dahlia, 62, 514 

Daisy, 516 

Dalbergia, 532 

Dammara, 413 

Dammar Resin, 413 

Dan«a, 378 

Dandelion, 512 

Dantzic Fir, 412 

Daplinales, 491 

Daphne, 492 

Darlingtonia, 182, 557 

Dasya, 277 

Date, germination of, 453 

Date Palm, 465 

Datisca, 521 

Datiscaceae, 521 

Datura, 102, 502 

Daucus, 519 

Daughter Cells, 39 

Day Lily, 460 

Deadly Nightshade, 502 

Death from high temperature, 188 

Death from low temperature, 189 

Decandrous, 432 

Dehiscence, 435 

Dehiscent, 435 

Delesseria, 277, 278 

Delphinium, 106, 564 

Dendrobium, 471 

Dentate Leaf, 147 

Denticella, 11 

Deoxidizatiou in Assimilation, 179 
j Dermatogen, 161, 423 
' Desmldiaceoe, 44, 225, 242, 336 

Desmids, 225 

Desmiospermese,' 340 

Desraobacteria, 213 

Desmodium, 196, 198, 436, 533 

Determinate Inflorescence, 428 

Deutzia, 526 

Diadelphous, 432 

Dialypetalous, 431 

Diandrous, 432 

Dianthus, 93, 550 



Diapensiacese, 508 
Diarthrodactylese, 334 
Diatoma, 227, 231 
Diatomaceee, 53, 227, 242, 336 
Diatoms, 34, 227, 242 
Diatrype, 294 
Dicarpellary, 433 
Di centra, 556 
Dichasium, 429 
Dichlamydeous, 431 
Dichogamous, 434 
Dichotomse, 382 
Dichotomous branching, 139 
Dichotomous Cyme, 429 
Dicksonia, 378 
Diclinous Flowers, 431 
Dicotyledones,393, 473, 568 
Dicotyledons, 93. 118, 123, 143, 148. 
150, 161, 200, 391, 416, 569, 570 
Dicranum, 360 
Dictamnus, 130, 132, 542 
Dictydium, 211 
Dictyotacese, 339 
Didymmm, 9, 10, 188, 210, 432 
Diervilla, 518 
Diffusion, 174 
Digitalis, 500 

Digitately lobed leaves, 147 
Digitately compound leaves, 148 
Digynous, 433 
Dill", 520 
Dillenia, 562 
Dilleniaceae, 562 
Dimensions of cells, 17 
Dimerous, 430 
Dimorphandra, 533 
Dimorphous, 434 
Dioecious, 249 
Dioecious Flowers, 431 
Diongea, 182, 197, 198, 52ti 
Dioscorales, 467 
Dioscorea, 467 
Dioscoreacese, 467, 473 
Diosma, 543 
Diosmeae, 542 
Diospyros, 506, 564, 565 
I'ipetalous, 432 
l)i])lostemonous, 433 
Diplosrephanae, 334 
T)il)sace8e, 516 
Dipsacus, 99, 516 
Dipterocarpese, 547 
Dirca, 492 
Direction of Spirals, 82 



o86 



GENERAL INDEX. 



Dirina, 809 

Discomycetes, 286, 338, 340 

Disepalous, 431 

Distribution in Time, 568 

Disturbance of the Equilibrium of 
Water, 168 

Diurnal Positions of Leaves, 199 

Division of Cells, 39, 49 

Divisions of the Vegetable King- 
dom, 205 

Docks, 497 

Dodder, 53, 56, 503 

Dodecandrous, 433 

Dcdecatheon, 506 

Dodongeae, 535 

Dogbane Family, 504 

Dogwood, 518, 539 

Dogwood Family, 518 

Dormant Buds, 144 

Doryphora, 494 

Double Cocoa-Nut, 465 

Doubly Compound Leaves, 148 

Douglas Spruce, 33, 411 

Doum Palm, 465 

Draba, 98, 264 

Dracaena, 444, 460 

Dracophyllum, 510 

Dragon Trees, 444, 460 

Dragon's Blood, 466 

Drosera. 183, 198, 429, 526 

Droseraceae, 526 

Drupaceous Fruits, 436 

Drupaceous Seeds, 437 

Drupe, 436 

Dry Fruits, 435 

Dryobalanops, 547 

Duckweeds, 461 

Dudresnaya, 376, 377 

Duguetia, 561 

Dulse, 377 

Dumontieae, 377 

Durio, 547 

Dwarf Almond, 530 

Dwarf Palmetto, 465 

Dyers' Weed, 553 

Earth-Star, 334, 326 
Ebenacege, 505, 564, 565 
Ebenales, 505 
Ebony, 506 
Ebony Family, 505 
Ecbalium, 11, 81 
Echinocystis, 74, 81, 533 
Echitps, 504 
EctoDlasm, 4. 15 



Edible Hymen omycetes, 330 

Eel Grass, 473 

Egg Plant, 500 

Elseagnaceae, 491 

Elaeagnus, 492 

Elaeis, 464 

Elaphomyces, 286 

Elaters, 348, 367 

Elatinaceae, 549 

Elder, 71, 126,144, 518 

Elecampane, 516 

Elements of Plant Food, 175 

Eleutheropetalous, 431 

Elliptical Leaves, 146 

Elm, 61, 64, 143, 146, 187, 488 

Elm Family, 488 

Embryo, 46, 391, 404, 433 

Embryology, 304 

Embryonic Vesicle, 47 

Embryo-sac, 11, 41, 46, 66, 137. 

389, 401, 403, 430 
Empusa, 241 
Encephalartos, 410 
Endive, 512 
Endocarp, 535 
Endocarpei, 310 
Endocarpon, 310 
Endochrome, 227 
Endogenae, 451 
Endoplasm, 4, 16 
Endosperm, 11, 41, 390, 403, 403. 

430, 433, 435 
Endospore, 34. 257, 363, 343 
English Bean, 38, 531 
English Ivy, 519 
English Walnuts, 480 
Enneandrous, 433 
Ensiform Leaf of Iris, 159 
Entomophilous Flowers, 431 
Entomophthora, 341 
Eutomopbthoraceae, 341, 339 
Epacrideae, 508, 510 
Epacris, 510 
Ephebe, 305, 309 
Ephedra, 413, 416 
Epidendreae, 470 
Epidendrum, 470 
Epidermal System, 90, 357, 362 

406 
Epidermis, 91, 93, 163, 170, 30t 

343, 363, 367, 393, 437 
Epigaea, 510 
Epigynous, 434 
Epigyny, 434 
lEpilobium. 6L523 



GENERAL INDEX. 



587 



Epi nasty, 199 

Epipetalous, 433 

Epispore, 257, 263 

Epithemia, 231 

Equilibrium of Water, 168 

Equisetacese, 35, 143, 368, 389 

Equisetinee, 362, 363, 382 

Equisetites, 369 

Equisetum, 11, 37, 80, 81,86, 88, 

110, 115, 120, 123, 128, 363, 368, 

369 
Erect Ovules, 433 
Ergot, 289, 295 
Erica, 510 

Ericaceae, 508, 564, 565 
Ericales, 508 
Ericinege, 508, 509 
Erigeron, 98 
Eriocaulonacese, 457 
Erodium, 543 
Erysimum, 437 
Erysiphaceae, 140, 278 
Erysiphe, 279, 383 
Erysipliei, 283 
Erythroxylon, 544 
Eschsclioitzia, 556 
Essence of Cinnamon, 63 
Essence of Wintergreen, 63 
Essential Oils, 62 
Ethiopian Lily, 462 
Etiolated Plants, 52 
Euastrum, 227 
Eucalyptus, 94, 524, 565 
Eudorina, 243 
Eugenia, 523 
Euglena, 50 
Eunotia, 231 
Euonymus, 539 
Eupatoriacese, 516 
Eupatorium, 264, 516 
Eupodisceae, 231 
Eupodiscus, 231 
Euphorbiaceee, 76, 77, 425, 484 
Euphorbiales, 484 
Euphorbia, 78, 102, 150, 485 
Euphorbium, Gum, 484 
Eurotium, 281, 285, 289 
Evaporation of Water, 167, 169, 

185, 191 
Evening Primrose, 61 
Everlasting Flowers, 515 
Evernia, 308 

Exalbuminous Seeds, 391, 437 
Excretions, 61 



Excoecaria, 485 
Exhalation of Water, 169 
Exoascus, 323 
Exocarp, 435 
Exogense, 473 
Exospore, 34, 222, 342 
Extine, 34 
Extrorse anthers, 433 

Fagopyriim, 496 

Fagus, 17, 150, 479, 564 

False Flax, 554 

False Raceme, 429 

Families of Cells, 65 

Farfugium, 514 

Fennel, 520 

P^ermentation, 212 

Fermentive Changes, 190 

Ferns, 123, 143, 155, 362, 370, 371, 

372, 373 
Fertilization in Angiosperms, 419. 

422 
Ferula, 520 
Fever Tree, 517 
Fibrous Roots, 165 
Fibrous Tissue, 74, 89, 106, 112, 

119, 123, 363, 368, 392 
Fibro-vascular Bundles, 106, 155, 

159, 352, 362, 367, 392. 407, 438 
Fibro-vascular System, 90, 106,343. 

359, 363, 438 
Ficoidales, 520 
Ficoideae, 520 

Ficus, 94, 102, 489, 564, 565 
Field Bean, 475, 531 
Field Oak, 480 
Fig, 61, 62, 437, 489 
Figwort Family, 500 
Filament, 394, 418 
Filbert, 477 

Filices, 370, 371, 372, 373, 389 
Filicinge, 369, 382, 389 
Fishes, growths on, 257 
Flagellarieae, 457 
Flax, 35, 181, 187, 188, 491, 543 
Flax Family, 543 
Fleshy Fruits, 435 
Flies, growths on, 257 
Floral Envelopes, 136, 155 
Floral Symmetry, 429 [340 

Florldese, 53, 186, 271, 273,335,337, 
Flower, 342, 353, 391, 394, 417 
Flower-axis, 136 
Flowering Dogwood, 518 



t>88 



GENERAL INDEX. 



Flowering Pliints, 203, 205 

Flowerless Plants, 208, 205 

Flowers, Colors of, 53 

Flowers in darkness, 192 

Flow of ISap, 174 

Fly-Fungus, 241 

Foeniculum, 520 

Foliage-leaf, 136 

Follicle, 436 

Fontinalis, 360 

Fool's Parsley, 520 

Foot, 386 

Forget-me-not, 502 

Forked Cyme, 429 

Forked Cymose Monopodium, 140 

Forked Dichotomy, 139 

Formation of Alkaloids, 182 

Formation of Ice Crystals, 189 

Formation of New Cells, 36 

Forms of Cells, 18, 19 

Forms of Leaves, 146 

Forms of Roots, 165 

Forsytliia, 505 

Fossil Characese, 334 

Fossil Cceloblasteae, 254 

Fossil Dicotyledons, 564 

Fossil Floride^, 278 

Fossil Fucacese, 269 

Fossil Gymnosperms, 415 

Fossil Helvellacese, 289 

Fossil Hymenomycetes, 331 

Fossil Lichens, 3i0 

Fossil Monocotyledons, 473 

Fossil Protophytes, 219 

Fossil Pyrenomycetes, 295 

Fossil Zvgosporeae, 242 

Four O'clock, 497 

Foxglove, 500 

Fragaria, 528 

Fragilaria, 227, 231 

Fragilariese, 281 

Framework of the Leaf, 155 

Frankeniaceae, 550 

Fraxinella, 540 

Fraxinus, 505, 565 

Free-cell Formation, 42, 47, 49 

Free Central Placenta, 434 

Free Oxygen, 179 

Fringe tree, 505 

Fritillaria, 460 

Frostweed, 552 

Fruits, 881, 426, 435 

Fruit Sugar, 62 

Fruit-Tangles, 339 

Frullania, 841, 351 



Frustule, 227 

Fucacese, 35, 53, 135, 186, 243, 264, 

268, 269, 886, 837 
Fuchsia, 61, 98, 94, 102, 104, 522 
Fucoidea3, 268, 269, 889 
Fucoides, 269 
Fucus, 265, 268 
Fuligo. 2, 10, 188, 194,210 
Fuller's Teasel, 516 
Fumariacese, 555 
Fumitory, 556 
Funaria, 352, 860 
Fundamental System, 90, 123, 359 

362, 363, 408, 438 
Fungales, 387 
Fungi, 13, 39, 53, 56, 66, 67. 86, 90 

192, 204, 205, 837, 340 
Punkia, 13, 460 
Fusanus, 476 
Fusiform Cell, 19 
Fustic, 490 

Galactodendron, 78, 489 

Galanthus. 468 

Gal i pea, 542 

Galium, 517 

Gamboge, 548 

Gamopetalse, 476, 497, 568 

Gamopetalous, 432 

Gamosepalous, 432^ 

Garcinia, 548, 549 

Garden Balsam, 542 

Gardenia, 518 

Garlic, 61, 68, 458 

Gas Plant, 540 

Gasteromycetes, 323, 324, 338, 340 

Gaultheria, 510 

Gaylussacia, 511 

Geaster, 324, 326 

Geissolomese, 484 

Gelidiese, 277 

Gelidium, 277 

Gemmae, 344, 357 

Generalized Forms, 133 

Generating Spiral, 151 

Genetic Relationship, 203 

Gentianacese, 503 

Geutianales, 503 

Gentian Family, 503 

Genuflexous Conj ugation, 234 

Georgia Bark, 517 

Geotropism, 194, 200 

Geraniaceae, 542 

Geraniales, 540 

Geranium, 548 



GENERAL INDEX. 



189 



Geranium Family, 542 

Gerardia, 53 

German Ivy, 514 

Germ-cell, 341, 348, 362, 390, 420 

Germination of Dicotyledons, 474 

Germination of Monocotyledons, 

451 
Germination of Seeds, 181, 187, 404 
Gesnera, 499 
Gesneracese, 499 
Giant PufE-ball, 326 
Giant Redwood, 411 
Giant Silver Fir, 412 
Gicrartineae, 277, 278 
Gilia, 503 
Gills, 328 
Gillyflower, 554 
Ginger, 472 
Gingerbread Palm, 465 
Ginkgo, 81, 399, 409, 410 
Ginseng, 518 
Gladiolus, 468 
Glands, 137 

Glandular Hairs, 97, 130 
Glandular Scales, 97 
Gleditschia, 533 
Gleichenia, 374, 376 
Gleiclieniacese, 376 
Globe Amaranth, 496 
Globe Flower, 564 
Globoids, 57 
Gloeocapsa, 216 

Glossology of Angiosperms, 426 
Gloxinia, 499 
Glucose, 62, 180, 181 
Glumales, 458 
Glycyrrhiza, 532 
Glyphidei, 310 
Glyphis, 310 

Gnetaceae, 396, 401, 410, 413 
Gnetum, 413 
Golden Lily, 460 
Golden Rod, 516 
Gomphonema, 229 
Gomplionemacese, 230 
Gomphrena, 496 
Gongylospermese, 340 
Gonidia, 217, 218, 219, 295, 301, 307 
Goodeniacese, 512 
Gooseberry, 62, 64, 283, 436, 526 
Gordonia, 548 
Gossypium, 426, 546 
Gourd, 29, 184, 522 
Gourd Family, 521 
Graminese, 94, 129,322,425,453,473 



Gramraatopliora, 231 

Granulose, 55, 56 

Grape, 62, 64, 264, 284, 288, 537 

Grape Mildew, 264 

Grapevine, 61 

Grapliidiacei, 310 

Grapliis, 301, 306, 310 

Grasses, 35, 93, 98, 102, 150, 187 

195, 289, 295, 316, 323, 421, 429. 

436, 464 
Grass Family, 453 
Gravitation and Geotropism, 194 
Great Laurel, 510 
Qreenbeart Tree, 494 
Green Hellebore, 460 
Grevillea, 491 
Grindelia, 516 
Ground Cherries, 500 
Ground Tissue, 89, 123 
Grouping of Living- Things, 203 
Growing Point, 87 
Growth of Cell-Walls, 22 
Guaiacum, 543 
Guavas, 523 
Guinea Pepper, 461 
Gulf- Weed, 269 
Gum, 62, 63. 129 
Gumbo, 547 
Gummy Substances, 96 
Gum Acacia, 533 
Gum Ammoniacum, 520 
Gum Arabic, 6 J, 533 
Gum Asafoetida, 520 
Gum Benzoin, 505 
Gum Copal, 533 
Gum Canals, 129 
Gum Euphorbium, 484 
Gum Galbanum, 520 
Gum Kino, 532 
Gum Lac, 490 
Gum Opopanax, 520 
Gum Storax, 505 
Gum Tragacanth, 63, 532 
Gunja, 488 

Gtitta Percha, 78, 506 
Giitti ferae, 548 
Gnttiferales, 547 
Gyalecta, 309 
GymnoascesG, 340 
Gyninoascus, 323 
Gymnocarpous Lichens, 297, 298 
Gymuocladus, 533 
Gyninospermae, 393, 568 
Gynmosperms, 60, 80, 85, 118, 123, 

391, 393, 437, 569, 570 



590 



GENFAIAL INDEX. 



Gymnosporangium, 314, 315, 817 

Gymnostemium, 469 

Gynandrous, 249. 433 

Gynoecium, 419, 430, 433 

Gypsophila, 550 

Gyrostomum, 309 

Habenaria, 470 

Hackberry, 488 

Hfemantbus, 171. 4G8 

Haematoxylon, 533 

Hsemodoraceae, 467 

Hairs, 90, 137 

Halesia, 505 

Halimeda, 254 

Halionyx, 231 

Halonia, 385 

Haloragese, 525 

Halosaccion, 277 

Hamamelacese, 526 

Hamamelis, 526 

Haplostepbanse, 334 

Hascbiscb, 488 

Hauptplasma, 4 

Haustoria, 258, 279, 317 

Hautscbicbt, 4 

Hawtborn, 428, 527 

Hazel, 187, 284 

Hazel Nut, 477 

Head, 428 

Heads, Racemose, 429 

Heads, Spicate, 429 

Heatb, 509 

Heatb Family, 508 

Heat-Rays of Spectrum, 193 

Hedeoma, 497 

Hedera, 103, 129, 165, 194, 519, 564 

Helenioidese, 514 

Heliampbora, 557 

Heliantbemum, 552 

Heliantbus, 62, 102, 151,284, 514 

Heliantboidese. 514 

Helicbrysam, 516 

Helicoid Cyme, 429 

Helicoid Mouopodium, 140 

Helicoid Sympodial Dicbolomy,140 

Heliopelta, 231 

Heliopeltese, 231 

Heliotrope, 502 

Heliotropism, 193, 200 

Heliotropium, 502 

Helipterum, 515 

Hellebore, 563 

Helleborus, 563 

Helmintbostachys, 380 



Helvella,289 

Helvellaceffi, 286, 28.J, 291. 2-95, 

299 
Hemerocallis, 159, 429, 460 
Hemiaulus, 231 
Hemi cyclic Flowers, 429 
Hemitelia, 377 
Hemlock, 520 
Hemlock Spruce, 154, 411 
Hemp, 61. 188, 488 
Henbane, 502 
Henna, 523 

Hepatica, 147, 187, 563 
Hepaticee, 343, 361 
Heppia, 309 
Heptandrous, 432 
Herd's Grass, 455 
Hermapbrodite Flowers, 431 
Hernandiese, 492 
Hernioid Protrusions, 30 
Hesperis, 554 
Heterocysts, 206, 217 
Heterodermese, 211 
Heteroecism, 314 
Heterogonous, 435 
Heterog-onous Dimorphous, 435 
Heterogonous Trimorpbous, 435 
Heteromerous Flowers, 430 
Heteromerous Licbens, 295, 301 
Heterosporese, 372, 383 
Heterostyled, 435 
Heterotbecium, 310 
Heucbera, 106 
Hevea, 78, 485 
Hexandrous, 432 
Hibiscus, 547 
Hickory, 144, 158, 483 
Hickory-nut, 73, 482 
Hieracium, 150 
Hilum of Starcb, 53 
Hippomane, 485 
Hippuris, 88 
Holly, 94, 539 
Holly Family, 539 
HoUybock, 547 
Homology and Analogy, 120 
Homoomerous Licbens, 395, 301 
Honey, 421 
Honey Locust, 533 
Honeysuckle, 199, 518 
Honesty, 554 
Hop. 61, 199. 283, 488 
Hop Tree, 542 
Hordeum, 455 



GENERAL INDEX. 



591 



Horehound, 497 
Hormospermese, 340 
Hornbeam, 477 

Horsechestnut, 58, 144, 429, 537 
Horsemiut, 498 
Horseradish, 63, 554 
Hottonia, 186 
Houseleek, 526 
Houstonia, 517 
Hoya, 61, 503 
Huckleberries, 511 
Hudsonia, 553 
Humiriacese, 543 
Humulus, 103, 488 
Hyacinth, 94, 102, 165, 460 
Hyacinthus, 460 
Hydnum, 338, 330, 331 
Hydra, 50 
Hydrales, 473 
Hydrangea, 526 
Hydrocarbons, 63 
Hydrocharidese, 473 
Hydrodictyon, 65, 223 
Hydrogen, 175, 179 
Hydrophyllacese, 502 
Hydrothyria, 309 
Hygroscopic Tissue, 157 
Hymensea, 533 

Hymenium, 278, 286, 297, 323 
Hymenophyllacese, 376 
Hymenophyllum, 376 
Hymenomycetes, 389, 323, 326, 33^ 

340 
Hyoscyamus, 502 
Hypericaceae, 549 
Hypericum, 132, 433, 549 
Hyphge, 194, 235 
Hyphsene, 465 

Hyphomjcetese, 323, 338, 340 
Hypnea, 377 
Hypne«, 377 
Hypnum, 360 

Hypocotyledonary Stem, 404 
Hypoderma, 73, 134 
Hypodermiae, 338 
Hypogynous, 434 
Hyponasty, 199 
Hypophysis, 434 
Hypoxylon, 394 
Hyssop, 497 
Hyssopus, 497 

Iberis, 441, 554 

Ice Crystals, formation of, 189 

Iceland Moss, 308 



Ice Plant, 530 

Ilex, 539, 565 

Iliciuese, 539, 565 

Imbibition power of Protoplasm, 

5, 168 [193, 364, 431, 543 

Impatiens, 14. 61, 85, 88, 159, 165, 
Imperfect Fungi, 333 
Incombustible substances, 35 
Incomplete flower, 431 
Incumbent cotyledons, 437 
Indehiscent, 435 
Indeterminate inflorescence, 428 
Indian Corn, 52, 56, 57, 59, 62, 70. 

106, 113, 114, 131, 155, 157, 165, 

166, 187, 318, 323, 451, 455, 523 
Indian Turnip, 61, 438 
Indian Pipe, 511 
India Rubber, 78, 485 
Indigo, 532 
Indigofera, 532 
Individual development, 204 
Indusium, 374 
Inflorescence, 427 
Innate Anthers, 433 
Insect agency in Pollination, 421 
Insect Fungi, 241 
Insects killed by parasitic plants, 

294 
Integument of ovule, 401 
Intercalary growth of cells, 23, 

140, 246 
Intercellular canal, 114, 409 
Intercellular spaces, 70, 99, 128, 

156, 167, 171, 197 
Intercellular substance, 35, 68 
Interfascicular cambium, 408 
Intermediate tissue, 125 
Internal cell-formation, 36, 39 
Internal structure of Leaves, 155 
Intine, 34 

Intrafascictilar Canal, 111 
Introrse anthers, 433 
Intussusception, 31, 54 
Inula, 62, 516 
Inulin. 62, 180 
Inuloidese, 515 
lonidium, 551 
Ipecacuanha, 517, 551 
Ipomoja, 14, 53, 70, 503 
Iridaceae, 468 
Iris, 61, 102, \m, 158, 468 
Iris Family, 468 
Irish Moss, 377 
Iron, 175 
Iron Bark Tree, 524 



502 



QENKliAL INDEX. 



Iron Salts, 17G 

Iron-weed, 516 

Iron wood, 284, 477. 505, 539 

Irregular dehiscence, 435 

Irregular flowers, 431 

Isatis, 554 

Isoetece, SS3, 387, 389, 391 

Isoetes, 382, 388, 403 

Isomerous flowers, 430 

Isonandra, 506 

Isosporese, 372, 383 

Isostemonous, 432 

Isthmia, 231 

Ivory Nut, 463 

Ivy, 98, 129, 16d, 194, 519 

Ixora. 518 

Jack Fruit, 489 

Jalap, 502 

Jamaica Cedar, 540 

Jamaica Ginjj^er, 473 

Jamaica Eosewood, 505 

Japanese Wax, 535 

Japan Lacquer, 535 

Japan Lily, 4:60 

Jarool, 523 

Jarrali, 524 

Jasminum, 505 

Jatropha, 484 

Jerusalem Articlioke, 515 

Jessamine, 505 

Joint-Firs, 410, 413 

Jonquil. 468 

Judas Trees, 533 

Juglandaceae, 480, 564 

Juglans, 102, 480,565 

Jujube, 539 

Juncace;©, 457 

Juncus, 131 

Jungermannia, 150, 349, 351 

Jungermanniacese, 345, 347, 351, 

358 
Juniperus, 17,81,410,411 
Justicia, 499 
Jute, 545 

Kaki, 506 
Kale, 553 
Kalmia, 510 
Kapor, 547 
Kaulfussia, 379 
Kauri Pine, 413 
Kentucky Blue Grass, 455 
Kentucky Coffee Tree. 533 



Khenna, 523 
Knightia, 491 
Koilreuteria, 537 
Kohl-Rabi, 554 
Kuline's Experiment, 9 



Labiatee, 71, 132, 497 

Laburnum, 532 

Lace-Bark Tree, 493 

Lacistemace*, 484 

Lacquer, 535 

Lactuca, 512 

Lactucarium, 512 

Lady's Slipper, 469, 543 

La3lia, 471 

Lsevulose, 62 

Lagenaria, 522 

Lagetta, 493 

Lagerstrcemia, 523 

Lambkill, 510 

Lamellae of Cell-wall, 68 

Lamiales, 497 

Laminaria, 268 

Laminarites, 269 

Lanceolate Leaves, 146 

Lance Wood, 561 

Lantana, 498 

Laportea, 491 

Larch, 185, 412 

Larix, 81, 409, 411, 413 

Larkspur, 564 

Larrea, 543 

Lateral Buds, 143 

Lateral Conjugation, 234 

Lateral Stems, 142 

Latex, 76 

Laticiferous Tissue, 67, 76, 106i 

119, 124, 363, 392 
Lathraea, 56 
Lathyrus, 532 
Latticed Cells, 17, 79, 111 
Lauraceae, 493, 565 
Laurales, 493 
Laurel, 493, 510 
Laurel Family, 493 
Laurelia, 494 
Laurus, 493, 564, 565 
Lavandula, 497 
Lavender, 497 
Lawsonia, 523 
Layers of Cell- wall, 34 
Lead-pencil Wood, 411 
Leaf. 136, 144, 197, 265, 369 



GENERAL INDEX. 



593 



Leaf-forms, 146 
Leaflet, 147 
Leaf -stalk, 145 
Leaf-tissue, 155 
Lecanactidei, 310 
Lecanactis, 301, 310 
Lecanora, 309 
Lecanorei, 309 
Lecidea, 310 
Lecideacei, 309 
Lecideei, 310 
Leek, 61, 458 
Left, To tbe, 199 
Legume, 436 

Leifuminosse, 426, 531, 565 
Leguminosites, 565 
Lejeunia, 351 
Lejolisia, 274, 277 
Lemna, 165 
Lemnacese, 461 
Lemon, 64, 130, 132, m 
Lemon Verbena, 498 
Lennoaceae, 508 
]jentibulariace8B, 499 
Lenticels, 126, 532 
Lenzites, 331 
Leon i a, 552 

Lepidium, 188, 264,425,554 
Lepidodendrege, 385 
Lepidodendron, 385 
Lepidopliloios, 385 
Lepidostrobus, 385 
Leptogium. 295, 306, 309 
Lessonia, 268 
Lettuce, 512 
Leucadendron, 491 
Leucobryum, 351 
Leucojum, 468 
Leucopogon, 510 
Lever-wood, 478 
Liatris, 429, 516 
Libocedrus, 411 
Licania, 531 
Licea, 211 
Lichenales, 337 
Liclienes, 295, 337, 340 
Lichens, 217, 218,295,338 
Lichina, 309 
Light, 169, 190. 197 
Lignification, 35 
Lignum-vitee, 543 
Ligule, 383. 386 
Li^ustrum, 505 



Lilac, 102, 126. 144, 158, 159, 284, 

505 
Lilac Blight, 140 
Liliace*. 94, 425, 458, 473 
Liliales, 457 
Lilium, 102, 460 
Lily, 94, 102, 460 
Lily Family, 458 
Lily-of-th«. Valley, 61, 460 
Lima Bean, 532 
Lime, 64, 541 
Lime Salts, 176 
Lime Tree, 545 
Limits of Temperature, 184 
Limnoria, 498 
Linacege, 543 
Linaria, 318 
Linden, 146, 545 
Linden Family, 545 
Linear Leaves, 146 
Linen, 544 
Linn, 545 
Linociera, 505 
Linseed Oil, 62, 544 
Linum, 543 
Liparis, 471 
Lippia, 498 
Liquidamber, 526 
Liquorice, 532 

Liriodendron, 72, 85, 562, 564 
Litchi, 537 

LithosDermum, 421, 436 
Litmus, 308 
Live-forever, 526 
Live-leaf, 526 
Live Oak, 479 
Liver-leaf, 187 

Liverworts, 91, 341, 343, 351, 356 
Loasacese, 522 
Lobelia, 511 
Lobeliacese, 77, 511 
Lobes of Leaves. 147 
Loblolly Bay, 548 
Loculicidal Dehiscence, 435 
Locust Tree, 61, 532, 533 
Lodoicea, 465 
Loganiaceae, 503 
Logwood, 533 
Lcmibardy Poplar, 487 
Loment, 436 
Lomentaria, 277 
Longan, 537 
Long-flowered Lily, 460 



594 



GENERAL INDEX. 



Long Moss, 47 

Longitudinal Tension, 201 

Lonicera, 518 

Lorantliacese, 477 

Love Flower, 460 

Love-in-a-Mist, 564 

Lucerne, 166, 532 

Luffa, 522 

Lunaria, 554 

Lupine, 58, 59, 533 

Lupin us, 582 

Lupulin, 488 

Lyclinis, 550 

Lyclinotbamnus, 334 

Lyciuni, 502 

Lycogola, 10 

Lycoperdon, 324, 325 

Lycopprsicum, 500 

Lycopodiacese, 80, 123, 383, 384. 

389 
Lycopodinse, 362, 382, 389 
Lycopodium, 81, 112, 121,123,150, 

382, 384, 385 
Lygodium, 374, 377 
Lysilonia, 534 
Lysiuiacliia, 506 
Lythraceai, 522 
Lytbrum, 523 



Mace, 494 

Madura, 102, 490 

Macrocystis, 268 

Macrogouidia, 219 

Macros porangj a, 373, 382, 386 

Macrospores, 362, 371, 373, 381, 

382, 386, 389, 403 
Macrozamia, 410 
Macrozoogouidia, 223 
Madder, 518 
Madeira Vine, 495 
Madrona, 509 
Magnesia Salts, 176 
Magnesium, 175 

Magnolia, 426, 437, 561, 564, 565 
Magnoliacea?, 561, 565 
Magnolia Family, 561 
Mahogany, 524. 540 
Mahonia. 559 
Maize, 455 
Malaxideae, 471 
Mai ax is, 471 
Malay Apple, 523 
Malic Acid, 64, 182 



Mallotium, 301, 306 

Mallow, 144, 147, 547 

Mallow Family, 546 

Malpigbiaceae, 543 

Malva, 85, 547 

Malvaceae, 98, 546 

Malvales, 544 

Mammea, 549 

Mammee Apple, 549 

Mamillaria, 151 

Maucbineel Tree, 485 

Mangel Wurtzel, 495 

Mangifera, 535 

Mango, 535 

Mangosteen, 548 

Mangrove Tree, 524 

Manibot, 484 

Manilla Hemp, 472 

Manzanita, 156, 509 

Manubrium, 381 

Maple, 77, 145, 147, 187, 284, 535 

Marauta, 473 

Marattia, 379 

Marattiacege, 363, 372, 378, 380 

Marcbantia, 14,344, 347, 348, 351 

Marcbantiaceae, 91,35© 

Marigold, 514 

Marmalade, 506 

Marrubium, 497 

Marsilia, 381, 382 

Marsiliaceae, 382 

Martynia, 98, 197, 499 

Marvel of Peru, 497 

Mastic, 535 

Mastigonema, 218 

Mastigonia, 231 

Mate, 540 

Matbematical Gymnastics, 153 

Mattbiola, 554 

Matisia, 547 

Maurandia, 500 

Maximum Ligbt, 191 

Maximum Temperature, 184 

Mayaceae, 457 

Ma> Apple, 437, 559 

Mayflower, 187, 510 

Meadow Grass, 166, 185 

Meadow Saffron, 460 

Meconic Acid, 182 

Medicago, 532 

Medullary RaA;s, 408, 449 

Megalospora, 298 

Melaleuca, 150 

Melambo Bark, 485 



GENERAL INDEX. 



595 



IVrelampsora, 314, 315 

Melanconiese, 323, 340 

Melanospermese, 268, 337 

Melaspilea, 310 

Melastomacese, 523 

Melia, 540 

Meliacese, 540 

Melianthese, 535 

Melicocca, 537 

Melon, 522 

Melosira, 231 

Melosirese, 231 

Members of the Plant Body, 133 

Menispermaceae, 560 

Menispermum, 560 

Mentlia, 497 

Menzies' Spruce, 412 

Mericarp, 436 

Merismopedia, 216 

Meristeui, 86, 168 

Meroxylon,532 

Mescal, 468 . 

Mesembryantliemum, 520 

Mesocarp, 435 

Mesocarpese, 235, 241, 242 

Mesocarpus, 235, 238 

Metaspermae, 393 

Metastasis, 62, 179, 186, 192 

Micrasterias, 227 

Microbacteria, 213 

Micrococcus, 213 

Microjronidia, 219, 304 

Micropyle, 391, 419 

Microsplisera, 281, 288 

Microsporangia, 372, 382, 386, 390, 

402, 418 
Microspores, 362, 371, 372,381, 382, 

386, 389 
Mignonette, 428, 552 
Mikania, 516 
Mildew, Grape, 264 
Milkweed Family, 503 
Mimosa, 197, 198, 534 
Mimoseae, 533 
Mimosites, 5G5 
Mimulus, 197, 500 
Minimum Light, 191 
Minimum Temperature, 184 
Mint Family, 497 
Mirabilis, 497 
Mistletoe, 53, 94, 182, 477 
Mistletoe Family, 477 
Mitella, 106 
Mitchella. 517 



Mixed Inflorescence, 428, 429 
Mnium, 353, 360 
Mock Orange, 526 
Modes of Branching, 139 
Molecules of Cell-wall, 32, 167 
Mollu-o, 520 
Monadelphous, 432 
Monandrous, 432 
Monarthrodactylae, 334 
Monera, 15, 207 
Monimiacese, 494 
Monizia, 520 
Monkey Flower, 500 
Monkey Pot, 524 
Monkshood, 562 
Monocarpellary, 433 
Monochasium, 429 
Monochlamydeous, 431 
Monoclinous Flowers, 431 
Monocotyled(mes, 393, 451, 568 
Monocotyledons, 88, 93, 123, 143, 

161, 318, 391, 416, 451, 569. 570 
Monocyclic, 430, 432 
Monoecious, 249; 431 
Monogvnoecial Fruits, 436 
Monogynous, 433 
Monomerous, 430 
Monopetalous, 431, 432 
Monopodial Branching, 13l{y 
Monosepalous, 431, 432 
Moiiosymmetrical Flowers, 431 
Monotropa, 192, 511 
Monotropese, 508, 510 
Monterey Cypress, 411 
Moonseed, 560 
Moose wood, 492 
Mora Tree, 533 
Moracese, 488, 565 
Morcheila, 289 
Morel, 289 
Mori:!g-ese, 534 
Morning Glory, 53, 199, 503 
Morphia, 182, 556 
Morphological Resemblances, 302 
Morphological Unit, 20 
Morphology. Special, 202 
Morus, 490 
Mosses, 46, 86, 92, 137, 143. 145i 

155, 194, 200, 341, 343, 351, 382 
Mother-cells, 39 
Moulds, 194, 235, 285, 288 
Mountain Ash, 64, 201 
Mountain Bay, 548 
Mountain Mahogany, 529 



506 



GENERAL INDEX. 



Movement of Water, 172 

Movements due to External Stim- 
uli, 197 

Movements of Nutation, 199 

Movements of Plants, 196 

Movements of Protoplasm, 6, 196 

Movements of Torsion, 200 

Mucilage, 35 

Mucor, 212, 236, 241 

Mucoraceae, 339 

Mucorini, 235, 242. 336 

Mulilenbergia, 455 

Mulberry, 61, 437, 490 

Mulberry Family, 488 

Mullein, 98, 500 

Mullein Pink, 550 

Multilocular, 433 

Mummy-cloth, 544 

Musa, 472 

Musse, 472 

Musci,343, 351 

Muscites, 360 

Mushroom, 328, 330 

Musk Tree, 516 

Mustard, 63, 98, 436, 554 

Mutisiacese, 512 

Mycelium. 235 

Mycetales, 337 

Mycoderma, 212 

Mycoporum, 310 

Myoporinea3, 498 

Myosotis, 502 

Myrica, 487, 564 

Myricacese, 487, 564 

Myristica, 494 

Myristicaceae, 494 

Myrrh, 540 

Myrsinaceae, 506 

Myrsiphyllum, 460 

Myrtacese, 425, 523, 565 

Myrtales, 522 

Myrtle Family, 523 

Myrtle (Trailmg), 504 

Myrtle Tree, 524 

Myrtus, 524 

Myxomycetes, 6, 10, 11, 15, 21, 36, 
44, 59, 60, 170, 178, 207, 336, 338 

Naiadacese, 128, 466, 473 

Naiads, 128 

Naias, 14 

Naked flow^ers, 431 

Narcissales, 467 

Narcissus, 61, 468 



Nasturtium, 543, 554 

Navicula, 230 

Naviculese, 230 

Neck -cells, 402 

Nectandria, 494 

Nectar, 421 

Negative Heliotropism, 193 

Negundo, 536 

Nelumbium, 131, 558 

Nemalion, 274, 277 

Nematospermeoe, 340 

Nemophila, 503 

Neottieaj, 470 

Nepenthacese, 482 

Nepeuthales, 482 

Nepenthes, 182, 482, 557 

Nephelium, 537 

Nephroma, 309 

Nereocystis, 268 

Nerium, 504 

Nettle, 11, 491 

Nettle Family, 490 

Neutral Flowers, 431 

Nicotiana, 502 

Nicotine, 182 

Nigella, 564 

Night-Blooming Cereus, 520 

Nightshade Family, 500 

Nipaceae, 463 

Nitella, 17, 200, 333 

Nitellese, 333 

Nitrates, 176, 180 

Nitrogen, 175, 180 

Nitzschia, 231 

Nocturnal positions of leaves, 19£ 

Norfolk Island Pine, 413 

Normandina, 310 

Norway Spruce, 412 

Nostoc, 37, 206, 217 

Nostocacege, 55, 216, 305, 306, 339 

Notelsea, 505 

Nucleoli, 16 

Nucleus, 16, 49, 206 

Number of Species, 566 

Number of Stomata, 102, 103 

Nuphar, 131 

Nut, 436 

Nutation, 199 

Nutgalls, 479 

Nutlets, 436 

Nutmeg, 494 

Nutmeg Family, 494 

Nut-oils, 482 

Nut Pine, 412 



GENERAL INDEX. 



597 



Nutrition of Parasites, 183 
Nutrition of Protoplasm, 180 
Nutrition of Saprophytes, 183 
Nux Vomica, 503 
Nyctaginacese, 497 
Nympb^a, 131,558 
Nympbgeaceaj, 128, 435, 557 
Nyssa, 519 

Oak. 64, 147, 172, 284, 421, 436, 

479 
Oak Family, 477 
Oat, 56, 58, 59, 166, 316, 318, 322, 

323, 455 
Oblong Leaves, 148 
Oclinacese, 540 
Ocbroma, 547 
Octandrous, 432 
CEdogoniaceae, 269, 271 
Oadogoniese, 246, 269, 336, 337 
OEdogonium, 10, 22, 42, 51, 350 
(Enotbera, 11, 98, 418, 532 
Oidium, 284 
Oil, 62, 129 
Oil-cake, 544 
Oil of Caraway, 63 
Oil of Juniper, 411 
Oil of Lavender, 497 
Oil of Lemons, 63 
Oil of Peppermint, 497 
Oil of Rhodium, 502 
Oil of Thyme. 63 
Oil of Turpentine, 63 
Oily Matter, 179, 181 
Okra, 547 
Olacales, 539 
Olacinese, 540 
Oldfieldia, 485 
Olea, 102, 505 
Oleacese, 504, 565 
Oleander, 94, 504 
Olearia, 516 
Oleaster, 493 
Olibanum, 540 
Oligomeris, 553 
Olive, 505 
Olive Family, 504 
Olive Oil, 63, 505 
Omphalaria, 306, 309 
Onagracese, 61, 533 
Onion, 61, 63. 77, 93, 199, 323, 458 
Onobrychus, 533 
Onygenese, 338 



Oogonium, 243, 267 
Oospore, 46, 56, 243, 268 
Oophyta, 205, 243, 369, 335, 337, 

568, 569, 570 
Oosphere, 45, 343, 267 
Opegrapba, 310 
Opegraphei, 310 
Open Bundle, 121, 443 
Opening of Flowers, 199 
Operculum. 355, 360 
Ophioglossaceffi, 371, 372, 379, '^!^4. 

389 
Qphioalossum, 80, 380. 381 
Ophrydeae, 470 
Opium, 78, 556 
Opium Poppy, 182, 556 
Opposite Leaves, 149 
Optimum Light,, 191 
Optimum Temperature, 184 
Opuntia, 150, 520 
Orange, 130, 132, 541 
Orang Lily, 460 
Orchard Grass, 455 
Orchidales, 468 
Orchidacese, 469 
Orchids, 137, 433, 469 
Orchil, 308 
Orchis, 470 
Ordeal Poison, 504 
Organic Acids, 180 
Organic Compounds as Food, 176, 

178 
Organogeny of the Flower, 426 
Orobauchaceae, 500 
Orobancbe, 56 
Ornithogalum, 461 
Ortbostichie& 149 
Oryza, 455 
Osage Orange, 490 
Oscillatoria, 37, 67, 217 
Oscillatoriaceje, 217 
Oscillatoriae, 53, 55 
Osmunda, 81, 377 
Osmundaceae, 377 
Ostrya, 73, 477 
Ourari, 503 
Ovary, 391, 417, 418 
Ovules, 136, 137, 390, 403, 419 
Oxalic Acid, 64, 180, 183 
Oxalis, 197, 435, 543 
I Ox Eye Daisy, 514 
j Oxidation in Metastasis, 179 
Oxidized Essences, 63 
I Oxygen, 175 



598 



GENERAL INDEX. 



Paeonia, 426, 564 

Palisade Tissue, 156 

Paliurus, 565 

Palm, 410, 443, 463, 473 

Palmaceae, 425, 463 

Palma Christa, 484 

Palmales, 462 

Palmately-compound Leaves, 148 

Palmately-lobed Leaves, 147 

Palmellacese, 51, 218, 306 

Palmetto, 465 

Palm Family, 463 

Palm Oil, 62, 464 

Palm Wine, 464 

Palmyra Palm, 465 

Panama Hats, 462 

Pandanacese, 462, 473 

Pan dan us, 462 

Pandorina, 10, 44,221, 242, 244, 336 

Panicle, 429 

Panicled Heads, 429 

Panicled Spikes, 429 

Panicum, 98 

Pannaria, 309 

Pannariei, 309 

Pansy, 551 

Papaver, 556 

Papaveracese, 77, 119, 556 

Papaw, 522, 561 

PapayaceaB( — Passifloracese), 119, 

522 
Paper Mulberry, 490 
Papilionaceae, 531 
Pappus, 512 
Papyrus, 457 
Paragfuay Tea, 540 
Paraphyses, 288, 292, 353 
Parasite, 53, 176, 178, 182, 190, 192, 

250, 270, 416 
Parasites, Roots of, 137 
Parasticbies, 151 
Paratonic Movements, 196 
Parencbyma, 18, 69, 90, 106, 119, 

124, 343, 351, 363, 392 
Parietales, 551 
Parietal Placenta, 434 
Parietaria, 150 
Parmelia, 306, 309 
Parmeliacei, 308 
Parmeliei, 309 
Paronychiese, 494 
Parsnip, 166, 187, 428, 519 
Partridge Berry, 517 
Passiflora. 522 



Passifloracese, 522 

Passiflorales, 520 

Passion Flower Family, 523 

Pasteur's Solution, 214 

Pastinaca, 519 

Pasture Tbistle, 514 

Paullinia, 537 

Paulownia, 500 

Pea, 56, 58. 59, 149, 187, 188, 284. 

436, 531 
Peacb, 62, 435, 530 
Peanut, 532 
Pear, 527 
Peat Mosses, 357 
Pecan Nut, 482 
Pectin, 63 
Pedaliaceae, 499 
Pediastrum, 65, 224 
Pelarsronium, 543 
Peltigera, 306, 309 
Peltigerei, 309 

Penicillium, 215, 238, 285,286, 289 

Pennyroyal, 497 

Pentacarpellary, 433 

Pentacyclic, 430 

Pentamerous, 430 

Pentandrous, 432 

Pentapetalous, 432 

Pentasepaious, 432 

Pentstemon, 500 

Peony, 58, 564 

Peperomia, 483 

Pepo, 436 

Pepper, 483, 561 

Pepper Family, 483 

Pepper Grass, 554 

Peppermint, 497 

Peppers, 501 

Pepperworts, 372, 381 

Peppridge, 519 

Periantb, 349, 418, 431 

Periblem, 162 

Pericambium, 110, 114, 162, 164 

Pericarp, 273, 275, 426, 435 

Pericbgetium. 342, 346 

Peridium, 312, 324 

Perigynous, 434 

Peril la, 498 

Periploca, 503 

Perisperm, 425 

PerisporiacesB, 273» 278, 340 

Peristome, 360 

Perithecium (pi.— a.), 281, 289, 297 



GENERAL INDEX. 



599 



Periwinkle, 33, 504 
Permanent Tissues, 86, 144 
Peronospora, 259, 264 
Peronosporacese, 339 
Peronosporese, 46, 258, 269, 317, 

337 
Persea, 494 
Persimmon, 506 
Personales, 498 
Pertusaria, 298, 809 
Peruvian Bark, 64, 182, 517 
Petal, 417, 430 
Petalostemon, 532 
Petiole, 145, 369 
Petunia, 98, 502 
Peyssonnelia, 277 
Peziza, 270, 271, 286, 288, 289,291, 

297, 301, 323, 330 
Pliacelia, 503 
Phacidium, 295 
Phseophycese, 339 
Pheeosporege, 265, 268, 269, 337, 339 
Phallus, 324, 325 
Phanerogamia, 204, 205, 389, 568, 

569, 570 
Phanerogams, 11, 40, 46, 56, 66, 72, 
74, 76, 82, 87, 90, 92, 106, 120, 
123, 137, 140, 161, 164, 265, 270, 
284, 316, 317, 389 
Phascacese, 355. 358 
Phascum, 358 
Phaseolus, 88, 475, 531, 533 

Pheasant's Eye, 564 

Phellodendron, 542 

Phellogen, 126 

Philadelphus, 103, 526 

Philydreae, 457 

Phleum, 455 

Phloem, 118, 407 

Phlox, 503 

Phoenix, 465 

Phoradendron, 51, 477 

Phosphates, 176 

Phosphorus, 175 

Phragmidium, 314, 315 

Phycocyanine, 216 

Phycomyces, 241 

Phycomycetes, 338 

Phycophyta, 339 

Phycophytes, 339 

Phycoxanthine, 216, 227 

Phyllactinia, 281, 283 

Phyllocladus, 410 

Phyllocyanine, 52 

Phylloglossum, 382, 385 



Phyllome, 134, 136, 243, 271 

Phyllotaxis, 149 

Phylloxanthine, 52 

Physalis, 500 

Physarum, 210 

Physcia, 296, 306, 309 

Physiological Unit, 20 

Physocalymma, 523 

Pliysomycetes, 338 

Phytelephas, 463 

Phytelephasiese, 463 

Phytolacca, 497 

Phytolaccaceae, 497 

Picea, 151,409,411,412 

Pie Plant, 497 

Pigeon Pea, 532 

Pileorhiza, 159,374, 424 

Pileus, 328 

Pilobolus, 237,241 

Pilophorus, 309 

Pilularia, 381, 382 

Pimento, 523 

Pinang, 466 

Pinckneya, 517 

Pine, 94, 412 

Pineae, 411 

Pine-apple, 62, 471 

Pine-apple Family, 471 

Pinguicula, 500 

PinhcBn Oil, 484 

Pink Family, 549 

Pinnately-compound Leaves, 148 

Pinnately lobed Leaves, 147 

Pinnate Venation, 145 

Pinus, 34, 69, 85. 102, 151, 395i 

397,409, 411,412,415 
Piper, 483, 561 
Piperacese, 425, 483 
Piperales, 483 
Pipsissewa, 510 
Piptocephalis, 238, 241 
Pirus, 72, 75, 85, 103, 527, 564 
Pistacia, 535 
Pistachia Nut, 535 
Pistil, 419. 433 
Pistillate Flowers, 431 
Pisum, 102, 531 
Pitch, 412 
Pitchers, 136 
Pitcher Plant, 556, 557 
Pith, 124, 128,200, 201,408 
Pits in Cell- walls, 24 
Pitted Vessels, 84, 113, 363 
Pittosporacese. 551 
Pittosporum, 551 



600 



GENERAL INDEX. 



Placenta, 419. 433 

Placodium, 309 

Plagiantlius, 547 

Plane Tree, 487 

Plane Tree Family, 487 

Platanaceae, 487, 565 

Platanus, 102, 487, 564, 565 

Platygraplia, 310 

Platyzoma, 376 

Plantaginaceae, 507 

Plantago, 106, 507 

Plantain, 106, 428, 472, 507 

Plantain Family, 507 

Plant Body, 133 

Plant-Cell, 15 

Plant Food, 175 

Plasmodium (pi.— a) 6, 207 

Plectospora, 302 

Plerome, 161 

Pleurocarpse, 359, 360 

Pleurocarpus, 235 

Pleurosigma, 230 

Plum, 62, 146, 292, 426, 530 

Plumbaginacese, 507 

Plumbago, 508 

Plumule, 186, 386, 404, 474 

Pbycoerytbrine, 276 

Poa, 279 455 

Podisoma, {see Gymnosporangium) 

Podocarpus, 409, 410 

Podogonium, 565 

Podopbyllam, 559 

Podospbsera, 271, 281, 283 

Pogonatum, 359 

Poison Hemlock, 520 

Poison Ivy, 165, 516, 535 

Poison Oak, 535 

Poison Sumacb, 535 

Poke-berries, 173 

Poke- weed, 497 

Pole Bean, 188, 531 

Polemoniacese, 503 

Polemoniales, 500 

Polemonium, 503 

Poliantbes, 461 

Pollen, 34, 46, 136, 389, 417 

Pollen-sac, 394. 418 

Pollen Tube, 47, 391 

Pollination, 420, 421 

Pollinia, 503 

Polyactis, 288 

Polyandrous. 432 

Polyantbus. 468 

Polyarthrodactylae, 334 



Polycarpellarv, 433 
Poly gal a, 55 1" 
Polygalacese, 550 
Polygiilales, 550 
Polygamous Flowers, 431 
PolvgonacejB, 64, 496 
P(^lygonum, 323, 496, 497 
Polygynoecial Fruits, 437 
Polyhedral Cell, 19 
Polyides, 277 
Polypetalfe, 476. 518 
Poly petal o us, 431, 432 
Polypodiacese. 377 
Polypodium, 109, 377 
Polypori, 241 
Polyporites, 331 
Polyporus, 328, 330, 331 
Polysepalous, 431, 432 
Polysiphonia, 277 
Polysipbonides, 278 
Polysymmetrical Flowers, 430 
Polytrichum, 150, 352, ^559- 360 
Pome, 436 
Pomeae, 527 
Pomegranate, 523 
Pondweeds, 466 
Pontederacese, 457 
Pontederales, 457 
Porcupine Grass, 157 
Portlandia, 518 
Poplar. 428 
Poppy, 556 
Poppy Family, 556 
Populus, 150, 487, 564, 565 
Populus, 102, 143 
Portulaca, 197, 264, 549 
Portulacacese, 549 
Potamales, 466 
Potamogeton, 131, 186 
Potasb Salts, 176 
Potassium, 175 

Potato, 56, 58, 166, 181, 187, 500 
Potato Fungus, 264 
Potentilla, 264 
Potentilleae, 528 
Prickles, 137 
Prickly Asb, 127, 542 
Prickly Pear, 520 
Pride of India Tree. 540 
Primary Bundle, 121 
Primary Cell-wall. 35, 68 
Primary Cortex, 408 
Primary Meristem, 86, 88, 89. 10(? 
121, 138, 144, 161 



GENERAL INDEX. 



GO! 



Primary Root, 159 
Primary Stem, 140 
Primary Wood, 406, 408 
Primine, 419 
Primordial Utricle, 5 
Primrose, 94, 98, 104, 506 
Primrose Family, 506 
Primula, 94, 98, 104, 506 
Primulaceae, 506 
Primulales, 506 
Prince's Pine, 510 
Principal Tissues, 69 
Pringslieimia, 250 
Prismatic Cell, 19 
Privet, 505 
Procambium, 121 
Pro-embryo, 332, 341, 391, 423 
Progressive Division, 49 
Promycelium, 314, 320 
Prosenchyma, 18 
Protamoeba, 15 
Protea, 491 
Proteacese, 491 
Proterandrous, 434 
Proterogynous, 434 [418, 420 

Prothallium (pi.— a), 361, 389, 403, 
Protococcoidese, 339 
Protococcus, 36, 37, 65, 185, 219 

221, 307 
Protodermese, 210 
Protomeristem, 86 
Protomycetes, 338 
Protomyxa, 15, 207 
Protonema (pi. — ata), 341, 356 
Protophyta, 205, 206, 306^ 335, 336, 

339, 568, 569, 570 
Protophytes, 206, 339 
Protoplasm, 1, 94, 166 
Protoplasm-Sac, 5, 15 
Prototaxis, 415 
Prototype, 134 
Protozoa, 207 
Prunese, 530 

Prunus, 102, 103, 530, 564 
Pseudolarix, 409 
Pseudopodium (pl._a). 8, 355 
Pseudo-Raphidieae, 230 
Pseudospores, 313 
Pseudotsuga, 411 
Psidium, 523 
Psilotum, 382, 385 
Ptseroxylon, 535 
Ptelea, 542 



Pteridopliyta, 205, 335, 361, CG8, 

369, 370 
Pteridopbytes, 10, 40, 59, 72, 74, 

80, 82, 86, 90, 92, 106, 121, 137, 

140, 161, 164, 361, 389, 418, 437 
Pteris, 72, 80, 81, 85. 88, 107, 110, 

111,369, 377 
Pterocarpus, 532 
Pterocarya, 565 
Pterophvllum, 416 
Puccinia, 39, 315, 316 
Puff-Ball, 324, 326 
Pulque, 468 
Pulse Family, 531 
Pulu, 378 
Pulvinus, 197 
Pumpkin, 29, 98, 187, 200, 436, 

437, 522 
Punica, 523 
Punctum Vegetationis, 87, 138, 140, 

144, 149, 424, 444 
Purslane, 93, 549 
Pycnidia, 281, 293, 299 
Pycnidiospores, 281, 294 
Pyrenastrum, 310 
Pyrenomycetes, 289, 295, 299, 338, 

340 
Pyrenula, 310 
Pyroliuete, 508, 510 
Pyxine, 309 
Pyxis, 436 

Quadril ocular, 433 
Quandang Nut, 476 
Quassia, 540 
Quercineae, 478 
Quercitron, 480 
Quercitron Oak, 480 
Quercus, 17, 85, 150, 479, 564 
Quernales, 477 
Quillaja, 529 
Quillaja Bark, 529 
Quillajeae, 529 
Quillworts, 387 
Quince, 35, 149, 527 
Quinia, 64, 517 
Quinic Acid, 64, 182 
Quinine, 517 

Raceme, 428 

Radial Bundle, 113, 362, 392 
Radiately-compound Leaves, 148 
Radiately-lobed Leaves, 147 



602 



GENERAL INDEX. 



Radiate Venation, 145 

Kadicle, 404, 474 

liudish, 98, 554 

Kafflesia, 270, 482 

Kafflesiacea?, 270,482 

Ragweed, 515 

Rainfall, 172 

Ramalina. 307, 308 

Ramie, 491 

Ramose Cell, 19 

Ranales, 466, 557 [562 

Ranuiiculace«, 284, 323, 425, 437, 

Ranunculus, 14, 117, 564 

RapatetE, 457 

Rape, 554 

Raplianus, 150, 554 

Raphides, 59, 61 

Rapliidieje, 230 

Raspberries, 64, 437, 529 

Rattan, 465 

Ravs of DiflFerent Refrangibilitv 
191 

Receptacle, 291, 349, 376, 381, 417 

Red Bay, 494 

Red Clover, 166 

Red Currant, 526 

Red -Hot Poker Plant, 4Gl 

Red Lily, 460 

Red Oak, 480 

Red Pine, 412 

Red Rust, 39, 316 

Red Sandalwood, 532 

Red Seaweeds, 53, 273 
. Red-Snow Plant, 185 

Red Top, 455 

Reduced Bundles, 121 

Redwood, 411 

Recrular Flowers, 430 

Reindeer Moss, 309 

Rejuvenescence, 42, 47, 229, 247 

Relations of Caulome, Pliyllome, 
etc. , 135, 138 

Relations to External Agents, 184 

Reproductive Cells, 47 

Reseda, 552 

Resedacese, 552 

Reserve Material, 181, 187 

Reservoirs for Secreti<nis, 129 

Residual Products, 01 

Resin, 62, 63, 129 

Resin Canals, 132 

Resinous Substances, 96 
RestiacesB, 457 



Restiales, 457 

Restio, 150 

Resting Spore, 218, 220 

Resting Stage, 208. 212 

Results of Metastasis, 183 

Resurrection Plant, 555 

Reticularia, 211 

Reticulated Thickenin^r, 28 

Reticulated Vessels, 83, 111 

Retinospora, 411 

Rhabdonema, 231 

Rliodanthe, 515 

Rhode rea3 511 

Rliamnaceae, 538, 565 

Rbamnus, 539, 565 

Rbeum, 71, 496 

Rbexia, 523 

Rbizocarpese, 370, 371, 372, 378 

381, 389 
Rbizocarps, 381 
Rbizoids, 343, 351, 361 
Rbizopbora, 524 
Rbizopboraceye, 524 

Rliizosolenia, 231 

Rliododendron, 510 

Rhodomeleee, 277, 278 

Rliodospermese, 337 

Rhodymenia, 277 

Rliodymeniese, 277 

Rhoicospbenia, 230 

Rhubarb, 61, 64, 496 

Rhus, 150, 165,535, 565 

Rhvtisma, 295 

Ribes, 102, 526 

Riccia, 346, 348, 349 

RicciaceiB, 350, 361 

Rice, 56, 59, 455 

Rice Paper, 519 

Ricbardia, 462 

Ricinus, 59, 85, 115 118 120. 475 
484 

Riga Fir, 412 

Right, to the, 199 

Ring, 328, 325 

Ringed Vessels, 83, 113 

Ringless Ferns, 372, 378 

Rings, 28 

Rinodina, 309 

Ripening of Seeds, 58 

Rivulariacese, 217 

Rivularia, 206, 218 

Robinia, 17, 61, 150, 533 

Roccella, 308 



GENERAL INDEX. 



603 



RocTiea, 106 

Rocket, 554 

Rock-weeds, 269 

Root, 134, 137, 159, 187, 190, 191 

243, 265, 362, 374, 404, 424 
Root-cap, 159, 161, 374, 404 
Root-hairs, 19, 95, 137, 161, 342 

351, 361, 367 
Root-pressure, 173 
Roots as Storehouses, 165 
Root- stock, 136 
Rosa, 527 

Rosacea, 64, 150, 425, 527, 565 
Resales, 524 
Roseae, 527 
Rose Apple, 523 
Rose Family, 527 
Rosemary, 497 
Rose Mallow, 547 
Rose of Jericho, 555 
Roses, 283, 437, 527 
Rosette, 402 
Rosewood, 505, 532 
Rosin, 63, 412 
Rosmarinus, 497 
Rotation of Organs, 199 
Rotation of Protoplasm, 14 
Rubege, 529 
Rubia, 518 
Rubiacese, 516 
Rubiales, 516 
Rubus, 529 
Rudbeckia, 151 
Rudiments of Floral Organs, 426, 

431 
Rue, 132, 542 
Rue Family, 541 
Rumex, 71,497 
Runners, 135, 193 
Ruscus, 461 
Rushes, 457 
Russia Leather, 487 
Rust, 316 
Ruta, 132, 542 
Rutacese, 541 
Ruteae, 542 
Rye, 94, 166, 289, 294, 295, 455 

Sabal, 465 

Sabiacese, 535 

Saccharomyces, 17, 39, 65. 214, 323 

Saccharomycetes, 323, 336 

Saccharum, 455 

back Tree, 490 



Safflower, 513 

Saffron, 468 

Sage, 498 

Sage Brusb, 514 

Sagedia, 310 

Sagittaria, 131, 467 

Sago, 410 

Sago Palms, 466 

Saguerus, 466 

Sagus, 466 

Salep, 470 

Salicacese, 425, 486, 565 

Salisburia, 410 

Salix, 486, 564, 565 

Salsify, 512 

Salvadoraceae, 504 

Salvia, 498 

Salvinia, 381, 382 

Salviniacese, 382 

Samara, 436 

Sambucus, 106, 518 

Samydaceae, 522 

Sanguinaria, 556 

Sandalwood Tree, 476 

Sand-box Tree, 485 

Sanfoin, 532 

SantalacesB, 476 

Santalales, 476 

Santalum, 476 

Santa Maria Wood, 549 

Sap, 62, 174 

Sapindacese, 535, 565 

Sapindales, 534 
Sapindese, 536 
Sapindus, 565 
Sapodilla Plum, 506 
Saponaria, 550 
Saponin, 461 
Sapotaceae, 506, 564 
Saprolegniaceae, 39, 56, 254, 263 

269, 337, 339 
Saprolegniae, 11 
Saprophyte, 53, 176, 178, 182, 190, 

221,250,270,281,286,323 
Sarcodes, 511 
Sargasso Sea, 269 
Sargassum, 268 
Sarracenia, 182, 556 
Sarraceniaceae, 556 
Sarsaparilla, 459 
Salt, diffusion of, 175 
Sassafras, 494, 564 
Sassafras Bark, 494 
Satin- Wood, 540 



^04 



GENERAL INDEX. 



Saunders, 532 

Saururus, 483 

Saw Palmetto, 465 

Saxifraga, 106, 198, 194, 520 

Saxifratraceae, 520 

Saxifrage Family, 520 

Scabiosa, 510 

Scalariform Thickening, 28 

Scalariform Vessels, 84, 107, 803 

Scales, 90, 180, 137, 155 

Scammony, 502 

Scarlet Bean, 187 

Scarlet Oak, 480 

Scattered. Leaves, 149 

Schalen, 34 

Schizomycetes, 178, 211, 330, 338 

Scbinus, 535 

Schizaea, 377 

Scliizseacese, 377 

Scbizocarpic Fruits, 436 

Schizopbycese, 339 

Scbizoxylon, 415 

Schizynemia, 277 

Scbulze's Maceration, 35 

Sciadopytis, 411 

Scilla, 459 

Scirpus, 150, 318 

Scitamineae, 471 

Sclerencbyma, 71, 89, 112, 124, 343, 

351. 303, 392 
Sclerotium, 290, 294 
Sclerotium Stage, 308 
Scolecite, 288 
Scolopendrium, 377 
Scorpioid Cyme, 429 
Scorpioid Monopodium, 140 
Scorpioid Sympodial Dichotomy, 

140 
Scotch Fir, 412 
Scotch Pine, 412 
Scouring Rushes, 35 
Screw Pine, 402 
Scrophulariacese, 500 
Scutellum, 451 
Scytonema, 218 
Scytonemacese, 218, 
Secale, 103. 455 
Secondary Cell- wall, 08 
Secondary Cortex, 408 
Secondary Embryo-sacs, 402 
Secondary Leaves, 147 
Secondary Spirals, 151 
Secondary Spores, 320 



Secondary Sporidiu, 320 

Secondary Wood, 408 

Secretion Reservoirs, 128 

Section-Cutter, 122, 105 

Sections of Leaf-buds, 154 

Secundine, 419 

Sedges, 318, 421 

Sedge Fjimily, 457 

Sedum, 150, 520 

Seed, 167. 181, 188. 391, 404, 420. 

437 
Segestria, 310 
Selaginella, 111, 112. 123, 382, 380, 

387 
Selaginellge, 121. 383, 385, 387, 391, 

397 
Sempervivum, 520 
Senecio, 514 
Senecionideae, 514 
Senna, 533 

Sensitive Plant, 197, 198, 534 
Sepal, 417, 430 
Septicidal Dehiscence, 435 
Sequoia, 81, 411, 415, 410 
Serrate Leaf, 147 
Service-Berries, 527 
Sesamum, 499 
Sesbania, 532 
Seta, 342, 355 
Setaria, 323 
Seville Orange, 541 
Sexual Act, 200 
Sexual Generation, 341, 361 
Sexual Organs, 200 
Shaddock, 541 
Shallot, 458 
Sheep Laurel, 510 
Shell-bark Hickory, 482 
Shells, 34 

Shepherdia, 98, 492 
Shepherd's Purse, 554 
Shields, 331 
Shower of Lichens, 309 
Sliowy Lily, 400 
Sida, 547 
Sieve Cells, 28 

Sieve Tissue, 79, 106, 363, 393 
Sigillaria, 385 
Sigillarieae, 885 
Silene, 550 
Silenese, 318 
Silicates, 176 
Silicon, 175 



QENEEAL INDEX. 



<J05 



Silique, 43G 

Silk Oak, 491 

Silk Tree, 547 

Silphium, 70, 71, 103, 132, 156. 

159, 515 
Silver-Bell Tree, 505 
Silver Fir, 413 
Silver Poplar, 173 
Silver Tree, 491 
Simaruba, 540 
Simaruba Bark, 540 
Simarubacese, 540 
Simple Leaf, 147 
Simple Pistil, 433 
Simultaneous Division, 49 
Single Cells, 65 
Sipbonese, 339 
Sirurella, 231 
Sirurellege, 231 
Sisymbrium, 98 
Size of Cells, 16 
Size of Leaves, 146 
Skimmia, 543 
Skunk Cabbage, 463 
Sleep of Plants, 198 
Slime Moulds, 6, 170, 188. 207 
Slippery Elm, 488 
Sloanea, 545 
Slougb Grass, 455 
Smartweed, 497 
Smilacina, 428 
Smilax, 459, 46Q 
Smut, 318, 333 
Snake wood, 490 
Snapdragon, 500 
Sueezewood Tree, 535 
Snowball, 518 
Snow berries, 518 
Snowdrop, 468 
Snowdrop Tree, 505 
Snow flake, 468 
Snow Plant, 511 
Soap Bark, 529 
Soda Salts, 176 
Sodium, 175 
Soft Bast, 116 
Solanacese, 71, 435, 500 
Solanum, 11, 103, 500 
Solidago, 516 

Solitary Axillary Inflorescence, 428 
Solitary Spores, 319 
Solitary Terminal Infioresceuce, 

439 



Sollya, 551 

Solorina, 309 

Solutions, 174 

Sonneratia, 533 

Sopbora, 533 

Soredia, 305 

Sorgbum, 457 

Sorosporium, 319, 333 

Sorrel, 497, 543 

Sorosis, 437 

Sorus (pi.— sori), 313, 374 

Soar Gum, 519 

Sour Sop, 561 

Soy, 533 

Spadix, 438 

Spanisli Bayonet, 461 

Spanish Chestnut, 478 

Spanish Needles, 515 

Sparganium, 463 

Speerschneidera, 309 

Spergula, 550 

Spermagonium (pi. — a), 293, 298, 

313 
Spermatium (pi.— a), 293, 299, 812, 

315, 333, 330 
Spermatozoids, 45, 46, 243, 267, 

271, 330, 333, 341, 363 
Sperm Cells, 341, 362 
Sphacelia, 389 
Sphaeria, 293, 394, 395 
Sphgerobacteria, 213 
Spbserococcites, 278 
Sphserococcoldeae, 377, 378 
Spbserophorei, 310 
Sphserophorus, 301, 310 
Spbseroplea, 345, 347 
Sphaeropsidese, 333, 340 
Spligerotheca, 281,283 
Sphagnacese, 352, 355, 356, 357 
Sphagnum, 351, 357, 358 
Splienophyllum, 368 
Spheroidal cell, 19 
Spicules, 324 
Spiderwort, 457 
Spike, 395, 438 
Spinach, 495 
Spinacia, 495 
Spines, 136 
Spiraea, 539 
Spirseeae, 529 
Spirals, 38 

Spiral Vessels, 83, 85, 108. 363 
Si)iranthes, 470 



606 



GENERAL INDEX. 



Spirillum, 213 

Spirobacteria, 213 

Spirochsete, 213 

Spirogyra, 11, 22, 37, 44, 51,57, 67, 

232, 234, 241 
Splaclinum, 359 
Spongiocarpese, 277 
Sporangium (pi.— a), 137, 210, 236. 

325, 366, 374, 378 
Spontaneous Movements, 196 
Spore-case, 342, 355 
Spores, 137, 170, 188, 209, 236, 342, 

361 
Spore-sac, 360 
Spore-Tangles, 339 
Sporidia, 290, 314, 317, 320 
Sporocarp, 270, 273, 274, 323, 327 
Sporog'onium(pl. — aj, 342, 348, 354 
Spumaria, 210 
^ Spurious Tissues, 65 
Spurge Family, 484 
Spyridia, 277 
Squamarieae, 277 
Squash, 29, 523 
Squill, 459 
Stachys, 441 
Stackhousieae, 539 
Stamen. 136, 197, 199, 894, 418, 430 
Staminate Flowers, 431 
Stapelia, 503 
Staphylea, 535 
StaphylesB, 535 
Star Apple, 506 

Starch, 53, 78, 165, 179, 181,187 
Starch Cellulose, 55, 56 
Star of Bethlehem, 461 
Stauroneis, 230 
Staurothele, 310 
Stellate Cell, 19 
Stem, 135, 140, 181, 187, 265 
Stemonitis, 9, 210 
Stephanodiscus, 231 
Stephanopyxis. 231 
Stephanotis, 503 
Sterculiacese, 545 
Stereum, 328, 330 
Sterigma (pi.— ata), 282, 299, 312, 

329 
Stereocaulon, 309 
Sticta, 296, 301, 309 
Stigeoclonium, 42 
Stigma, 197, 419 
Stinging Nettles, 491 
Stink-Hom, 325 



Stipa, 103, 157 

Stipules, 148 

Stoffwechsel, 180 

Stoma (pi. stomata), 39, 90, 91, 92 
99, 155, 170, 185, 191, 312, 343 
350, 352, 359, 362, 367, 392, 437 

Stomata, Number of, 102, 103 

Storing of Reserve Material, 181 

Stratification of Cell-wall, 32, 93 

Strawberries, 62, 64, 434, 529 

Strawberry Geranium, 526 

Strawberry Tomato, 500 

Streaming of Protoplasm, 6 

Strehtzia, 472 

Striatella, 231 

Striation of Cell-wall, 33 

Strigula, 310 

Strings of Protoplasm, 16 

Strobile, 437 

Strychnia, 182, 503 

Strychnos, 182, 503 

Stuartia, 548 

Styles, 199 

Stylidiace89, 512 

Stylidium, 512 

Stylospores, 39, 293, 315 

Styracaceae, 505 ^ 

Styrax, 505 

Sucrose, 62 

Sugar, 62, 165, 455 

Sugar Beet, 62, 495 

Sugar Cane, 62, 93, 495 

Sugar, Diffusion of, 175 

Sugar Maple, 62, 174, 535 

Sugar Pine. 412 

Sugary Matter, 179 

Sulphates, 176, 180 

Sulphur, 175, 180 

Sulphuretted Essences, 63 

Sumach, 64, 535 

Sumatra Camphor, 547 

Summer Buds, 141 

Sundew, 526 

Sundew Family, 526 

Sunflower, 159, 171, 173, 188, 436, 
514 

Sunflower Family, 512 

Supernumerary Buds, 143 

Supernumerary Stems, 143 

Supple Jacks, 537 

Supporting Tissue, 89 

Suppression of Floral Organs, 431 

Suspended Ovules, 433 

Suspension of Movements, 198 



GENERAL INDEX. 



607 



Suspensor, 385, 391, 404, 423 
Swarmspores, 36, 209, 222, 260, 

268, 273 
Sweet Alyssum, 554 
Sweet Bay, 562 
Sweet Gum-Tree, 526 
Sweet Oil, 505 
Sweet Potato, 143, 165, 502 
Sweet Sop, 561 
Swietenia, 540 
Symmetry of Leaves, 146 
Sympetalous, 432 
Sympodial Cymose Monopodium, 

140 
Sympodial Dichotomy, 140 
Symphoricarpus, 11, 462, 518 
Synalissa, 309 
Synantherous, 433 
Syncarpous, 433 
Synedra, 231 
Syngenesious, 433 
Sycamore, 487 
Syconus, 437 
Syringa, 102,505 
Systems of Tissues, 89 
System of Ground Tissues, 123 
f 

Tabell aria, 231 
Tabellarieae, 231 
Tabernaemontana, 504 
Tabular Cell, 19 
Taccacese, 468 
Taccades, 468 
Tagetes, 514 
Tallow Tree, 485 
Tamarack, 412 
Tamarind, 64, 533 
Tamarind us, 533 
Tamariscineae, 549 
Tamarisk, 549 
Tamarix, 549 
Tauacetum, 514 
Tan bark Oak, 480 
Tanghin, 504 
Tanghinia, 504 
Tannic Acid, 64, 182 
Tansy, 514 
Taraxacum, 62, 512 
Tares, 532 
Tarichium, 241 
Tartaric Acid, 64, 182 
Tar, 412 
Tapioca, 484 
Taxiueae, 400, 410 



Taxodieae, 411 

Taxodium, 409, 411 

Taxus, 102, 395, 399, 409, 410 

Tea, 182, 548 

Teak, 485, 498 

Teasel, 516 

Tecoma, 499 

Tectona, 498 

Tegmen,' 437 

Tela Contexta, 66 

Teleutospores, 313 

Temperature, 169, 184, 198 

Tendril, 136, 200 

Teredo, 524 

Termes, 524 

Terminal Growth of Cells, 22 

Ternstroemiaceae, 548 

Terpsinoe, 231 

Tetracarpellary, 433 

Tetracyclic, 430 

Tetradynamous, 432 

Tetramerous, 430 

Tetrandrous, 432 

Tetranthera, 494, 565 

Tetraphis, 357 

Tetrapetalous, 432 

Tetrasepalous, 431 

Tetraspores, 273 

Testa, 426, 437 

Testudinaria,-467 

Tliallopliyta, 203, 204, 205 

Thallophytes, 17, 18, 37,- 56, 90, 

140, 145, 205, 264, 357 
Thallophytes, Classification of, 835 
Thallome, 134, 243 
Thallus, 342, 461 
Thamnochortus, 150 
Thea, 548 
Theca, 355 

Theloschistes. 307, 309 
Thelotrema, 309 
Theobroma, 545 
Theobromine, 546 
Theories as to Thickening of the 

Cell-wall, 30 
Thespesia, 547 
Thickeninor of Cell -wall, 23 
Thistles, 99, 187, 513 
Thorn Apple, 502 
Tliorus, 136 
Thrift, 508 
Thunbergia, 499 
Thuya, 409, 411 
Thyme, 497 



608 



GENERAL INDEX, 



Thymelseaceae, 492 

Thymus, 497 

Thyrsus, 429 

Tieute, 503 

Tiger Lily, 460 

Tilia, 150, 545 

Tiliaceae, 545 

Tillandsia, 471 

Tilletia, 318. 322 

Timothy, 455 

Tipularia, 470 

Tissues, 65, 69, 343, 358, 3G2, 3(57, 

405 
Tissues of Angiospenns, 4:J7 
Tissue Systems, 80 
Tjettek, 503 
Tmesipteris, 382, 385 
Toadstools, 39 
Tobacco, 182, 184, 502 
Toddaliege, 542 
Toddy Palms, 466 
Todea, 377 
Tolypella, 333, 334 
Tomato, 98, 164, 500 
Torreya, 409, 410 
Torsion, 200 
Torus, 417 
Touch-Me-Not, 542 
Towel Gourd, 522 
Tracheary Tissue, 81, 106, 363, 392 
Tracheides, 84, 116, 407 
Trachylobium, 533 
Trachymene, 520 
Tradescantia, 11, 12, 13, 61, 98, 45'; 
Tragopogon, 512 
Trailing Arbutus, 510 
Trailing Myrtle, 504 
Transitory Rigidity, 198 
Transformation of Starch, 180 
Transpiration, 169, 185 
Transportation of Food, 176 
Transverse Tension, 201 
Trapa, 164, 522 
Tree Ferns, 146, 373, 377, 410 
Tree Nettle, 491 
Tree of Heaven, 541 
Tremaudreae, 551 
Tremella, 289 
Tremellini, 323, 330, 338 
Triadelphous, 432 
Triaudrous, 432 
Tricarpellary, 433 
Trichia, 2V 



Trichobasis, 316 

Trichogyne, 271, 286, 300 

Trichomanes, 376 

Tricliome, 92, 95, 134. 137, 161,346. 

362, 392, 437 
Trichophore, 275 
Tricyclic, 430 
Trifolium, 103, 533 
Trigvnous, 433 
Trilocular, 433 
Trimerous, 430 
Trimorphous, 435 
Tri petal ous, 432 
Trisepalous, 431 
Triticuni, 453 
Tritoma, 461 
I'riurales, 467 
Triuridese, 467 
Trollius, 564 
Tropoeolum, 106, 543 
Truffle, 285 
Trvpethelium, 310 
Tsuga, 33, 150, 409, 411 
Tuber, 136, 181, 190, 191, 285, 286 
Tuberaceee, 273, 285, 338, 340 
Tuberose, 461 
Tubulina, 211 
Tulip, 93, 102, 461 
Tulipa, 461 
Tulipomania, 461 
Tulip Tree, 523, 562 
Tulip Wood, 537 
Tumble Weed, 496 
Tupelo, 519 
Turban Lilv, 460 
Turgidity of Cells, 167 
Turkey Oak, 480 
Turk's Cap Lily, 460 
Turmeric, 472 
Turneraceae, 522 
Turnip, 166, 185, 554 
Turpentine, 63, 409, 412 
Turpentine Canals, 130 
Twigs, 181 

Twilling of Organs, 200 
Typha, 462 
Typhaceee, 462 

Ullucus, 495 
Ulmacese, 488 
Ulmus, 150, 488 
Ulva, 225 
Ulvacese, 67 



GENERAL INDEX. 



609 



tJmbel, 428 

Umbellales, 418 

Umbelliferse, 129, 43G, 519 

Umbel lularia, 494 

Umbilicaria, 298, 301, 309 

Umbilicariei, 309 

Umbrella Tree, 562 

Uncinula, 281, 283 

Unicorn Plant, 499 

Unilocular, 433 

Uni parous Cyme, 429 

Unisexual Flowers, 431 

Upas Tieute, 503 

Upas Tree, 490 

Urari, 503 

Urceolaria, 298, 309 

Uredinese, 310, 317, 820, 337, 840 

Uredo, 316 

TJredospore, 312 

Urocystis. 320, 323 

Uromyces, 315 

Uropyxis, 315 

Urtica, 11, 61, 491 

Urticacese. 61, 77, 490 

Urticales, 488 

Usnea, 296, 301, 306, 308 

Usneei, 808 

Ustilaginege, 317, 337, 340 

Ustilago, 318, 322 

Utricle, 436 

Utricularia, 182, 500 

Vaccinieae, 508, 511 
Vaccinium, 511, 565 
Vacuoles, 5, 51, 167, 189, 197 
Valerian, 516 
Valeriana, 516 
Valerianaceae, 516 
Vallisneria, 14. 186, 473 
Valsa, 294 

Valves of Diatoms, 227 
Vandeae, 470 
Vanilla, 470 
Vascular Bundle, 106 
Vascular Cryptogams, 361 
Vascular Plants, 205 
Vascular Tissues, 119 
Vaucheria, 10, 45, 250, 254 
Vaucberiacese, 254, 269 
Vegetable Alkaloids, 64 
Vegetable Jelly, 63 
Vegetable Mucilage, 63 
Vegetative Cells. 49 



Vegetative Cone, 87 

Vegetative Point, 87 

Veil, 328 

Veins of Leaves, 145 

Venation, 145, 475 

Venice Turpentine, 412 

Ventral Suture, 433 

Venus' Fly-Trap, 526 

Veratrum, 459 

Verbascum, 150, 500 

Verbena, 98, 284, 498 

Verbeuacese, 498 

Vermiform Body, 288 

Vernonia, 516 

Vernoniaceae, 516 

Veronica, 500 

Verrucaria, 306, 310 

Verrucariacese, 310 

Verrucariei, 310 

Versatile Antliers. 433 

Vervain Family, 498 

Vessel-cells, 17 

Vessels, 66, 167 

Vetch, 58, 59, 149, 533 

Vibrio, 213 

Viburnum, 17, 127, 518, 565 

Vicia, 14, 38, 150, 531, 532 

Victoria, 146, 558 

Victoria Lily, 558 

Vinca, 33, 102, 428, 504 

Vine, 61, 171, 174, 193. 537 

Viola, 421, 436, 551 

Violacpse, 425, 551 

Violet Family, 551 

Violets, 551 

Virginia Creeper, 61, 155, 165, 193; 

538 
Virgin's Bower, 284, 564 
Viscum, 477 
Vitex, 498 

Vitis, 81, 85, 103, 150, 174, 537 
Vocliysia, 550 
Vochjsiaceae, 550 
Volvoclnese, 221, 339 
Volvox. 223, 243, 268, 269, 337 
Vulcanized Rubber, 485 

V^aaboo, 539 
Wagen-boom, 491 
W^aking of Plants, 198 
Walking-sticks, 269 
Wallflower, 554 
Walnut,, 42t. 480 



CIO 



GENERAL INDEX. 



Walnut Family, 480 

Wasbingtonia, 465 

Water as Plant Food, 176 

Water Chestnut, 522 

Water Chinquepiu, 558 

Water Cress, 554 

Water Hemlock, 520 

Water in Cell-walls, 167 

Water in Intercellular Spaces, 167 

Water in Protoplasm, 166 

Water in the Plant, 166 

Water Lily, 71, 128, 558 

Water Lily Family, 557 

Watermelon, 188, 522 

Water of Organization, 33, 179 

Water Plantain, 128 

Water Plantain Family, 466 

Water pores, 104 

Water Net, 223 

Water- Slimes, 339 

Water Weed, 473 

Wattles, 533 

Wax Palm, 93, 464, 466 

Wax Plant, 503 

Weeping Trees, 196 

Weeping Willow, 487 

Weigelia, 518 

West India Birch, 540 

West India Locust, 533 

Weld, 552 

Welwitscliia, 413, 415 

Wheat, 56, 59, 98, 187, 316, 318, 

323, 428, 453 
White Ash, 505 
White Cedar, 411 
White Clover, 166 
White Elm, 488 
White Hellebore, 459 
White Ipecacuanha, 551 
White Light, 192 
White Lily, 460 
White Mulberry, 490 
White Mustard, 188, 554 
White Oaks, 479 
White Pepper, 483 
White Pine, 412 
White Poplar. 173 
White Spruce, 413 
Whitlavia, 503 
Whorls of Leaves, 149 
Whortleberry, 64 
Wicopy, 492 
Wild Black Cherry. 530 
Wild Cucumber, 522 



Willow, 64, 127, 143, 284, 486 

Willow Family, 480 

Windsor Bean, 474 

Winged Seeds, 487 

Winter Buds, 141 

Winter Cherry, 500 

Wintergreen, 510 

Wistaria, 532 

Witch Hazel, 526 

Wolffia, 461 

Wood, 447 

Wood -cells, 17, 34, 173 

Wood Fibres, 74, 119 

Wood Nettle, 491 

Wood Sorrel, 543 

Woorara, 503 

Wormia, 562 

Worm seed, 495 

Wormwood, 514 

Wrack, 269 

Wrangelia, 277 

Wrangeliacege, 377 

Xanthium, 515 
Xanthorrhoea, 461 
Xanthosia, 520 
Xanthoxyleae. 543 
Xanthoxylum, 127, 132 542 
Xylem, 118, 201, 407 
Xylographa, 310 
Xylomites, 295 
Xylopia, 561 
Xylophylla, 485 
Xyridacese, 457 

Yam Family, 467 

Yeast Plant, 17, 39, 314, 333 

Yellow Pine, 413 

Yellow Poplar, 562 

Yellow Thistle, 514 

Yew, 93, 4:0 

Yucca, 461 

Yuccites, 473 

Yulan Tree, 563 

Zamia, 410 
Zamiostrobus, 416 
Zea, 11. 88, 102, 113, 455^ 
Zebra Poison, 485 
Zebra Wood, 534 
Zingiber, 473 
ZingiberacesR, 473 
Zinnia, 53, 514 
Zizyphus, 539, 565 



GENEBAL INDEX. 



611 



Zonotrichia, 218 
Zoogloea Stage, 213 
Zoogonidium, 221, 252 
Zoospore, 42, 66, 221, 241, 245, 271 

302 
Zoosporese, 221, 241, 244, 269 
Zostera, 13 



Zygnema, 51, 67. 234 
Zygnemacege, 232, 242, 336 
Zygomoiphic, 431 
Zygophyllaceae, 543 
Zygospore, 220 

Zygophyta, 45, 205, 220, 242, 244, 
306, 335, 336, 568, 569, 570 



h 



M:4e4 



a 




n mS 337 2429. 




